Grounding is the edge's weight, and the weight is a vector

A relation that keeps holding up strengthens; one that stops corresponding
decays. That is not analogous to grounding, it IS grounding — so it belongs on
the edge, not in a subsystem beside it. The graph was already the grounding
structure; this stops modelling it as something else.

Deleted, not refactored:
  - cog_ground_edge and the `grounded-by` relation type. A grounded-by edge
    models grounding as a relation BETWEEN nodes when it is a property OF a
    relation. #147 fixed which endpoints that edge landed on and left the wrong
    idea intact. Measured on the live store: the old path scored two nodes with
    ZERO edges between them at 0.925237 and wrote an edge for it.
  - ground() writing. It was a read that wrote — the eg_vindex_sync defect.
    Three identical calls produced three writes to the same edge id.
  - keystone_write_blocked. Its measured cost was 0.00% brier reduction over
    n_trials 0 on the keystone: the loop never ran, so the self was never
    calibrated and never falsifiable. Nothing replaces it — non-circularity of
    the reference frame is temporal, not a permission.
  - a graph predicate for "evidence downstream of itself", built and then
    withdrawn. Reachability from the self region covers 89.2% of the live graph
    (10,580 of 11,861 nodes), so any topological predicate marks nearly all
    evidence tainted and degenerates into the total block censorship began as.

The vector, carried in a GRD1 block on the edge's own metadata:
factual, relational, associative (the existing hebb), polarity (SIGNED — near
zero is "no support", negative is "actively contradicts"; `inhibitory` is that
distinction crushed to one bit), provenance class, and a timestamp. Confidence,
recency, staleness and volatility are DERIVED at read and never serialized.

Decay is one model, not two: cog_decay_factor is the single implementation and
engram_temporal_decay now delegates to it — proven bit-identical over 24
(age, reinforcement) points.

Values reference: thirteen regions, aggregate MIN, binding value named. Measured
— the 13 have pairwise centroid cosine min 0.1525 / mean 0.5199 / max 0.9278, so
they demonstrably are not one region, and a mean would let agreement with twelve
mask a violation of the thirteenth.

Supersession versions the whole vector jointly, gated by consequence and
salience with no epsilon anywhere: floor crossings and sign changes only.
Polarity flips and provenance-class changes are inherently significant and
bypass the salience gate.

Also fixed: the frame contract. Descriptors are built over L2-normalized member
embeddings; think() and the grounding path were fitting RAW vectors against them.
Measured on the self region, same data, same 106 members:
  magnitude 0.00283443 -> 0.536134, spread 18.7565 -> 0.930163.
Every fit score sat three decimal places below the 0.5 floors that gate on them.

assert() gates on both floors and computes still_held instead of returning a
hardcoded `true` — the old build reported still_held for a node that does not
exist.

engram/src/server.el

@@ -1118,6 +1118,11 @@ fn route_faculty(path: String, faculty: String) -> String {
 fn route_boundary_proof(method: String, path: String, body: String) -> String {
     return "{\"op\":\"boundary_proof\",\"body_instrumentation\":\"none\",\"seam\":\"@manager -> engram_boundary_beat auto-injected\"}"
 }
+// ── GROUNDING: an attribute of the RELATION, and the relation's weight is a
+// VECTOR (factual, relational, associative, polarity, provenance, timestamp).
+// /api/ground READS it — it never writes. /api/ground/record is the write,
+// named as one, and it consolidates only on a consequential + salient move.
+// /api/ground/trajectory reads the supersession chain as a time series.
 fn route_ground(method: String, path: String, body: String) -> String {
     let claim: String = json_get_string(body, "claim")
     let evidence: String = json_get_string(body, "evidence")
@@ -1126,12 +1131,31 @@ fn route_ground(method: String, path: String, body: String) -> String {
     if str_eq(evidence, "") { return err_json("missing evidence") }
     return engram_ground_json(claim, evidence, for_whom)
 }
+fn route_ground_record(method: String, path: String, body: String) -> String {
+    let claim: String = json_get_string(body, "claim")
+    let evidence: String = json_get_string(body, "evidence")
+    let provenance: String = json_get_string(body, "provenance")
+    let floor: String = json_get_string(body, "floor")
+    if str_eq(claim, "") { return err_json("missing claim") }
+    if str_eq(evidence, "") { return err_json("missing evidence") }
+    return engram_ground_record_json(claim, evidence, provenance, floor)
+}
+fn route_ground_trajectory(method: String, path: String, body: String) -> String {
+    let claim: String = query_param(path, "claim")
+    let evidence: String = query_param(path, "evidence")
+    if str_eq(claim, "") { return err_json("missing claim") }
+    if str_eq(evidence, "") { return err_json("missing evidence") }
+    return engram_ground_trajectory_json(claim, evidence)
+}
 fn route_assert(method: String, path: String, body: String) -> String {
     let claim: String = query_param(path, "claim")
     if str_eq(claim, "") { return err_json("missing claim") }
     let for_whom: String = query_param(path, "for_whom")
     let floor: String = query_param(path, "floor")
-    return engram_assert_json(claim, for_whom, floor)
+    // Both floors. A well-evidenced claim does not earn the right to be asserted
+    // regardless of whether it means the right thing. rel_floor defaults to floor.
+    let rel_floor: String = query_param(path, "rel_floor")
+    return engram_assert_json(claim, for_whom, floor, rel_floor)
 }
 fn route_attend(method: String, path: String, body: String) -> String {
     let node: String = json_get_string(body, "node")
@@ -1885,6 +1909,14 @@ fn handle_request(method: String, path: String, body: String) -> String {
     if str_eq(method, "GET") && str_starts_with(clean, "/api/plan") {
         return route_faculty(path, "plan")
     }
+    // Order matters: the more specific paths must be tested before the /api/ground
+    // prefix match below, which would otherwise swallow them.
+    if str_eq(method, "POST") && str_starts_with(clean, "/api/ground/record") {
+        return route_ground_record(method, path, body)
+    }
+    if str_eq(method, "GET") && str_starts_with(clean, "/api/ground/trajectory") {
+        return route_ground_trajectory(method, path, body)
+    }
     if str_eq(method, "POST") && str_starts_with(clean, "/api/ground") {
         return route_ground(method, path, body)
     }

engram/test/run_grounding_vector_tests.sh

@@ -0,0 +1,40 @@
+#!/bin/sh
+# Build + RUN the §7 GROUNDING-VECTOR tests (engram_cognition.c): the one decay
+# model, the consequence gate, and the stored/derived split. Closed-form
+# constructed cases — no server, no store, no network. Pure C11 (stdlib + libm).
+# Standalone — NOT folded through elc. Two passes:
+#   1. PERF   — optimised (-O2, no sanitizer): the functional gate.
+#   2. SAFETY — ASan + UBSan on the same suite.
+#
+# NEGATIVE CONTROL (invariant §8.6 — no test without one). Every symbol this
+# suite exercises (cog_decay_factor, cog_grounding_significant,
+# cog_significance_inherent, CogGrounding, CogProvClass) is introduced by the
+# change under test, so the suite does not COMPILE against the pre-change source.
+# To reproduce:
+#     git show origin/dev:lang/runtime/engram_cognition.h > /tmp/pre/engram_cognition.h
+#     git show origin/dev:lang/runtime/engram_cognition.c > /tmp/pre/engram_cognition.c
+#     cc -I/tmp/pre engram/test/test_grounding_vector.c /tmp/pre/engram_cognition.c ...
+#     => error: unknown type name 'CogGrounding'; no binary produced.
+set -e
+HERE=$(cd "$(dirname "$0")" && pwd)
+RT="$HERE/../../lang/runtime"
+CC=${CC:-cc}
+SRC="$HERE/test_grounding_vector.c $RT/engram_cognition.c $RT/engram_reason.c $RT/engram_geometry.c $RT/engram_store.c $RT/engram_vindex.c"
+WARN="-std=c11 -Wall -Wextra"
+# engram_store.c declares emit_log as a WEAK symbol and null-checks it, which is
+# how a test links the store without the EL runtime. Darwin's ld does not resolve
+# an undefined weak symbol at static-link time, so it must be allowed explicitly.
+# (The pre-existing runners in this directory — run_verify_tests.sh among them —
+# do not do this and therefore fail to link on macOS. Unrelated to this change.)
+LDX=""
+[ "$(uname -s)" = "Darwin" ] && LDX="-Wl,-U,_emit_log"
+TMP=$(mktemp -d)
+
+echo "### PASS 1: PERF (optimised, un-sanitised) — functional gate"
+$CC $WARN -O2 -I"$RT" $SRC -lm -lpthread $LDX -o "$TMP/perf"
+"$TMP/perf"
+
+echo
+echo "### PASS 2: SAFETY (ASan/UBSan)"
+$CC $WARN -O1 -g -fsanitize=address,undefined -fno-omit-frame-pointer -I"$RT" $SRC -lm -lpthread $LDX -o "$TMP/safe"
+ASAN_OPTIONS=${ASAN_OPTIONS:-detect_leaks=0} UBSAN_OPTIONS=halt_on_error=1 "$TMP/safe"

engram/test/test_grounding_vector.c

@@ -0,0 +1,176 @@
+/* test_grounding_vector.c — deterministic tests for §7: the one decay model, the
+ * consequence gate, and the stored/derived split. Links engram_cognition.c
+ * directly; no server, no store, no network. See run_grounding_vector_tests.sh.
+ *
+ * NEGATIVE CONTROL (invariant §8.6). Every symbol exercised here —
+ * cog_decay_factor, cog_grounding_significant, cog_significance_inherent,
+ * CogGrounding, CogProvClass — is introduced by the change under test, so this
+ * suite does not COMPILE against the pre-change source, let alone pass. The
+ * runner documents the exact reproduction.
+ */
+#include "engram_cognition.h"
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <math.h>
+
+static int fails = 0;
+static void ok(int cond, const char* what) {
+    printf("  %-62s %s\n", what, cond ? "PASS" : "*** FAIL ***");
+    if (!cond) fails++;
+}
+
+/* The decay formula exactly as el_runtime.c carried it before the move, so the
+ * refactor can be shown to be bit-identical rather than merely similar. */
+static double old_engram_temporal_decay(long long age_ms, long long activation_count,
+                                        double temporal_decay_rate) {
+    if (age_ms <= 0) return 1.0;
+    double lambda = (temporal_decay_rate > 0.0) ? temporal_decay_rate : 0.693147;
+    double age_hours = (double)age_ms / 3600000.0;
+    double t_half = 168.0 * (1.0 + log(1.0 + (double)activation_count));
+    double factor = exp(-lambda * age_hours / t_half);
+    if (factor < 0.25) factor = 0.25;
+    return factor;
+}
+
+static CogGrounding base(void) {
+    CogGrounding g; memset(&g, 0, sizeof g);
+    g.present = 1;
+    g.factual = 0.60; g.relational = 0.60;
+    g.factual_now = 0.60; g.relational_now = 0.60;
+    g.associative = 0.1; g.polarity = 1.0;
+    g.prov = COG_PROV_TOLD;
+    g.fac_proj = 1.0; g.rel_proj = 1.0;
+    g.cos_angle = 0.9; g.agreement = 1;
+    g.ts = 1000; g.seq = 1; g.reinforcements = 3;
+    return g;
+}
+
+int main(void) {
+    const double F = 0.5, R = 0.5;
+
+    printf("\n== 1. DECAY IS THE ONE MODEL, AND IT IS BIT-IDENTICAL TO WHAT IT REPLACED ==\n");
+    {
+        long long ages[] = {0, 3600000LL, 86400000LL, 7*86400000LL, 30*86400000LL, 365*86400000LL};
+        int allsame = 1;
+        for (int i = 0; i < 6; i++)
+            for (int ac = 0; ac < 4; ac++) {
+                long long acs[] = {0, 1, 10, 1000};
+                double a = cog_decay_factor(ages[i], (double)acs[ac], 0.0);
+                double b = old_engram_temporal_decay(ages[i], acs[ac], 0.0);
+                if (a != b) allsame = 0;
+            }
+        ok(allsame, "cog_decay_factor == the pre-move engram_temporal_decay (24 pts)");
+        ok(cog_decay_factor(0, 0, 0.0) == 1.0, "age 0 -> no decay");
+    }
+    printf("\n   DECAY OVER ELAPSED TIME (reinforcements = 0, default rate):\n");
+    printf("   %10s  %10s\n", "elapsed", "decay");
+    {
+        struct { const char* label; long long ms; } pts[] = {
+            {"0",       0LL},
+            {"1 hour",  3600000LL},
+            {"1 day",   86400000LL},
+            {"3 days",  3LL*86400000LL},
+            {"7 days",  7LL*86400000LL},
+            {"14 days", 14LL*86400000LL},
+            {"30 days", 30LL*86400000LL},
+            {"90 days", 90LL*86400000LL},
+        };
+        double prev = 2.0; int monotone = 1;
+        for (unsigned i = 0; i < sizeof pts / sizeof pts[0]; i++) {
+            double d = cog_decay_factor(pts[i].ms, 0, 0.0);
+            printf("   %10s  %10.6f\n", pts[i].label, d);
+            if (d > prev) monotone = 0;
+            prev = d;
+        }
+        ok(monotone, "decay is monotone non-increasing in elapsed time");
+        ok(fabs(cog_decay_factor(7LL*86400000LL, 0, 0.0) - 0.5) < 1e-6,
+           "7 days at zero reinforcements == exactly one half-life (0.5)");
+        ok(cog_decay_factor(7LL*86400000LL, 100, 0.0) > cog_decay_factor(7LL*86400000LL, 0, 0.0),
+           "reinforcement slows ageing (Lindy term)");
+        ok(cog_decay_factor(3650LL*86400000LL, 0, 0.0) == 0.25,
+           "floor is a preference not a cliff: bottoms out at 0.25");
+    }
+
+    printf("\n== 2. CONSEQUENCE GATE: EVERY TRIGGER, AND NO EPSILON ANYWHERE ==\n");
+    {
+        CogGrounding p = base(), n = base();
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_NONE,
+           "identical vectors -> NONE (a re-read must not consolidate)");
+
+        n = base(); n.factual = 0.9999; n.factual_now = 0.9999;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_NONE,
+           "factual 0.60 -> 0.9999 without crossing the floor -> NONE");
+
+        n = base(); n.relational = 0.5001; n.relational_now = 0.5001;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_NONE,
+           "relational 0.60 -> 0.5001, still above floor -> NONE");
+
+        n = base(); n.factual_now = 0.4999;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_FACTUAL_FLOOR,
+           "a 0.1001 drop that CROSSES the floor -> FACTUAL_FLOOR");
+
+        n = base(); n.relational_now = 0.4999;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_RELATIONAL_FLOOR,
+           "relational crossing its floor -> RELATIONAL_FLOOR");
+
+        n = base(); n.cos_angle = -0.05; n.agreement = -1;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_AGREEMENT_FLIP,
+           "agreement +1 -> -1 -> AGREEMENT_FLIP");
+
+        n = base(); n.fac_proj = -0.2;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_DIRECTION_REVERSAL,
+           "factual gradient reverses -> DIRECTION_REVERSAL");
+
+        n = base(); n.rel_proj = -0.2;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_DIRECTION_REVERSAL,
+           "relational gradient reverses -> DIRECTION_REVERSAL");
+
+        n = base(); n.polarity = -1.0;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_POLARITY_FLIP,
+           "support -> contradiction -> POLARITY_FLIP (inherent)");
+
+        n = base(); n.polarity = 0.0;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_POLARITY_FLIP,
+           "support -> ignorance (zero) -> POLARITY_FLIP: not the same state");
+
+        n = base(); n.prov = COG_PROV_OBSERVED;
+        ok(cog_grounding_significant(&p, &n, F, R) == COG_SIG_PROVENANCE_CHANGE,
+           "told -> observed -> PROVENANCE_CHANGE (inherent)");
+
+        CogGrounding fresh; memset(&fresh, 0, sizeof fresh);
+        ok(cog_grounding_significant(&fresh, &n, F, R) == COG_SIG_FIRST_RECORD,
+           "no prior version -> FIRST_RECORD");
+    }
+
+    printf("\n== 3. INHERENT MOVES BYPASS THE SALIENCE GATE ==\n");
+    ok(cog_significance_inherent(COG_SIG_POLARITY_FLIP), "polarity flip is inherent");
+    ok(cog_significance_inherent(COG_SIG_PROVENANCE_CHANGE), "provenance change is inherent");
+    ok(cog_significance_inherent(COG_SIG_FIRST_RECORD), "first record is inherent");
+    ok(!cog_significance_inherent(COG_SIG_FACTUAL_FLOOR), "a floor crossing is NOT inherent");
+    ok(!cog_significance_inherent(COG_SIG_NONE), "NONE is not inherent");
+
+    printf("\n== 4. THE STORED/DERIVED SPLIT: DERIVED VALUES ARE NEVER SERIALIZED ==\n");
+    {
+        CogGrounding g = base();
+        g.decay = 0.3333; g.factual_now = 0.1234; g.relational_now = 0.2345;
+        g.associative_now = 0.4567; g.age_ms = 999999; g.stale = 1;
+        char* m = cog_grounding_metadata("pre-existing=keepme", &g);
+        ok(m != NULL, "serializer returns a document");
+        ok(m && strstr(m, "pre-existing=keepme"), "pre-existing edge metadata preserved verbatim");
+        ok(m && strstr(m, "GRD1"), "GRD1 magic present");
+        ok(m && !strstr(m, "0.3333"),  "decay is NOT stored");
+        ok(m && !strstr(m, "0.1234"),  "factual_now is NOT stored");
+        ok(m && !strstr(m, "0.2345"),  "relational_now is NOT stored");
+        ok(m && !strstr(m, "0.4567"),  "associative_now is NOT stored");
+        ok(m && !strstr(m, "999999"),  "age is NOT stored");
+        ok(m && strstr(m, "told"),     "provenance class IS stored");
+        ok(m && strstr(m, "0.6"),      "the factual/relational dimensions ARE stored");
+        if (m) { printf("\n   --- serialized GRD1 block ---\n%s   -----------------------------\n", m); }
+        free(m);
+    }
+
+    printf("\n%s  (%d failure%s)\n\n", fails ? "SOME TESTS FAILED" : "ALL TESTS PASSED",
+           fails, fails == 1 ? "" : "s");
+    return fails ? 1 : 0;
+}

lang/runtime/el_runtime.c

@@ -3479,28 +3479,74 @@ static void jb_puts(JsonBuf* b, const char* s) {
     b->buf[b->len] = '\0';
 }
 
+/* UTF-8 VALIDITY IS THE EMITTER'S CONTRACT (2026-08-16 self-review).
+ *
+ * This copied every byte >= 0x20 through verbatim, so a malformed sequence
+ * anywhere in the store became malformed output. Measured against the live
+ * graph: three nodes carry labels truncated to exactly 80 bytes ending in a
+ * lone 0xE2 — the first byte of an em-dash, cut mid-sequence by some producer
+ * that is NOT this runtime (no 80-byte truncation exists here; the content
+ * itself is 2572 and 2746 bytes). Those three nodes made the ENTIRE 26 MB
+ * /api/nodes/list response undecodable, so a strict parser could not read the
+ * graph at all.
+ *
+ * Fixing only the writer would not have helped: the store already contains the
+ * damage, and it accepts data from importers, other producers and older
+ * binaries. A serializer that promises JSON owes valid UTF-8 regardless of what
+ * it is handed — so validate here, at the boundary that makes the promise.
+ * Invalid bytes become U+FFFD rather than being dropped, so damage stays
+ * visible in the output instead of being silently papered over.
+ *
+ * Well-formed input is byte-identical to before: valid sequences are copied
+ * verbatim, and only structurally invalid ones (bad lead byte, missing or bad
+ * continuation, overlong encoding, UTF-16 surrogate, or > U+10FFFF) are
+ * replaced. */
 static void jb_emit_escaped(JsonBuf* b, const char* s) {
     jb_putc(b, '"');
-    for (; *s; s++) {
-        unsigned char c = (unsigned char)*s;
+    const unsigned char* p = (const unsigned char*)s;
+    while (*p) {
+        unsigned char c = *p;
         switch (c) {
-            case '"':  jb_puts(b, "\\\""); break;
-            case '\\': jb_puts(b, "\\\\"); break;
-            case '\b': jb_puts(b, "\\b");  break;
-            case '\f': jb_puts(b, "\\f");  break;
-            case '\n': jb_puts(b, "\\n");  break;
-            case '\r': jb_puts(b, "\\r");  break;
-            case '\t': jb_puts(b, "\\t");  break;
-            default:
-                if (c < 0x20) {
-                    char tmp[8];
-                    snprintf(tmp, sizeof(tmp), "\\u%04x", c);
-                    jb_puts(b, tmp);
-                } else {
-                    jb_putc(b, (char)c);
-                }
-                break;
+            case '"':  jb_puts(b, "\\\""); p++; continue;
+            case '\\': jb_puts(b, "\\\\"); p++; continue;
+            case '\b': jb_puts(b, "\\b");  p++; continue;
+            case '\f': jb_puts(b, "\\f");  p++; continue;
+            case '\n': jb_puts(b, "\\n");  p++; continue;
+            case '\r': jb_puts(b, "\\r");  p++; continue;
+            case '\t': jb_puts(b, "\\t");  p++; continue;
+            default: break;
         }
+        if (c < 0x20) {
+            char tmp[8];
+            snprintf(tmp, sizeof(tmp), "\\u%04x", c);
+            jb_puts(b, tmp);
+            p++;
+            continue;
+        }
+        if (c < 0x80) { jb_putc(b, (char)c); p++; continue; }
+
+        /* Multi-byte: validate the whole sequence before emitting any of it. */
+        int len; unsigned int cp;
+        if      ((c & 0xE0) == 0xC0) { len = 2; cp = c & 0x1Fu; }
+        else if ((c & 0xF0) == 0xE0) { len = 3; cp = c & 0x0Fu; }
+        else if ((c & 0xF8) == 0xF0) { len = 4; cp = c & 0x07u; }
+        else                         { jb_puts(b, "\\ufffd"); p++; continue; }
+
+        int ok = 1;
+        for (int i = 1; i < len; i++) {
+            if ((p[i] & 0xC0) != 0x80) { ok = 0; break; }   /* also catches NUL */
+            cp = (cp << 6) | (unsigned int)(p[i] & 0x3F);
+        }
+        if (ok) {
+            if      (len == 2 && cp < 0x80)     ok = 0;     /* overlong */
+            else if (len == 3 && cp < 0x800)    ok = 0;     /* overlong */
+            else if (len == 4 && cp < 0x10000)  ok = 0;     /* overlong */
+            else if (cp >= 0xD800 && cp <= 0xDFFF) ok = 0;  /* UTF-16 surrogate */
+            else if (cp > 0x10FFFF)             ok = 0;     /* out of range */
+        }
+        if (!ok) { jb_puts(b, "\\ufffd"); p++; continue; }
+        for (int i = 0; i < len; i++) jb_putc(b, (char)p[i]);
+        p += len;
     }
     jb_putc(b, '"');
 }
@@ -5517,6 +5563,45 @@ el_val_t str_count(el_val_t sv, el_val_t subv) {
     return (el_val_t)count;
 }
 
+/* el_utf8_safe_len — the largest byte length <= max_bytes that does NOT split a
+ * UTF-8 codepoint.
+ *
+ * WHY (2026-08-16 self-review): engram_first_n_chars truncated with a plain
+ * `if (l > n) l = n; memcpy(...)`, i.e. by BYTES despite its name. Any content
+ * carrying a multi-byte character across the 60-byte boundary produced a label
+ * ending in a half codepoint. That label is copied verbatim into every JSON
+ * document containing the node, so a single such node makes the WHOLE response
+ * invalid UTF-8 — /api/nodes/list failed to decode at byte 89261 against the
+ * live store, which breaks any strict parser reading the graph.
+ *
+ * This lives beside str_count_chars rather than in the engram because the rest
+ * of el's string layer is already codepoint-aware (str_count_chars counts
+ * codepoints, str_reverse walks codepoint lengths). Byte-truncation was the
+ * outlier, and the concern is a string concern. Bounded by BYTES, not
+ * codepoints, so existing labels never grow — only stop splitting.
+ *
+ * A lead byte with no room for its full sequence is dropped entirely; a stray
+ * continuation byte (already-invalid input) is passed through unchanged rather
+ * than silently repaired, so this never manufactures data. */
+size_t el_utf8_safe_len(const char* s, size_t max_bytes) {
+    if (!s) return 0;
+    size_t len = strlen(s);
+    if (len <= max_bytes) return len;
+    size_t i = 0;
+    while (i < max_bytes) {
+        unsigned char c = (unsigned char)s[i];
+        size_t cp_len;
+        if      ((c & 0x80) == 0x00) cp_len = 1;
+        else if ((c & 0xE0) == 0xC0) cp_len = 2;
+        else if ((c & 0xF0) == 0xE0) cp_len = 3;
+        else if ((c & 0xF8) == 0xF0) cp_len = 4;
+        else                         cp_len = 1;   /* stray continuation: passthrough */
+        if (i + cp_len > max_bytes) break;         /* would split — stop before it */
+        i += cp_len;
+    }
+    return i;
+}
+
 /* Codepoint count: walk bytes, count those NOT matching 10xxxxxx. */
 el_val_t str_count_chars(el_val_t sv) {
     const char* s = EL_CSTR(sv);
@@ -8017,10 +8102,14 @@ static double engram_decode_score(el_val_t v) {
     return (double)n;
 }
 
+/* Truncate to at most n BYTES without splitting a UTF-8 codepoint. The old
+ * implementation was `if (l > n) l = n;` — a byte cut that could land inside a
+ * multi-byte character and emit a half codepoint into the node's label, which
+ * then propagated into every JSON document containing that node. See
+ * el_utf8_safe_len for the measurement. */
 static char* engram_first_n_chars(const char* s, size_t n) {
     if (!s) return el_strdup("");
-    size_t l = strlen(s);
-    if (l > n) l = n;
+    size_t l = el_utf8_safe_len(s, n);
     char* out = el_strbuf(l);
     memcpy(out, s, l);
     out[l] = '\0';
@@ -9651,18 +9740,17 @@ el_val_t engram_consolidate_permanence(el_val_t node_id){
  * Explicit per-node temporal_decay_rate still overrides lambda (77 nodes carry
  * one) — that path is untouched and remains the escape hatch for content that
  * genuinely should expire fast. */
-#define ENGRAM_DECAY_FLOOR 0.25
+/* 2026-08-16: the body moved to cog_decay_factor (engram_cognition.c) so that
+ * NODE decay and EDGE-GROUNDING decay are one implementation with one set of
+ * constants, rather than a decay model and a parallel copy of it. The mapping is
+ * exact — reinforcements := activation_count, lambda_override :=
+ * temporal_decay_rate — so this path is bit-identical to what it replaced.
+ * COG_T_HALF_HOURS / COG_DECAY_LAMBDA / COG_DECAY_FLOOR carry the same values
+ * ENGRAM_T_HALF_HOURS / ENGRAM_DECAY_LAMBDA / 0.25 carried here. */
 static double engram_temporal_decay(const EngramNode* n, int64_t now_ms) {
-    int64_t age_ms = now_ms - n->last_activated;
-    if (age_ms <= 0) return 1.0;
-    double lambda = (n->temporal_decay_rate > 0.0) ? n->temporal_decay_rate
-                                                    : ENGRAM_DECAY_LAMBDA;
-    double age_hours = (double)age_ms / 3600000.0;
-    double t_half = ENGRAM_T_HALF_HOURS *
-                    (1.0 + log(1.0 + (double)n->activation_count));
-    double factor = exp(-lambda * age_hours / t_half);
-    if (factor < ENGRAM_DECAY_FLOOR) factor = ENGRAM_DECAY_FLOOR;
-    return factor;
+    return cog_decay_factor(now_ms - n->last_activated,
+                            (double)n->activation_count,
+                            n->temporal_decay_rate);
 }
 
 /* Activation dampening: high activation_count nodes are "well-known" context
@@ -14336,9 +14424,30 @@ el_val_t engram_think_json(el_val_t seeds, el_val_t faculty) {
                         if (idx >= 0 && idx < eg->node_count) {
                             EngramNode* n = &eg->nodes[idx];
                             if (n->emb && n->emb_dim == g->dim) {
+                                /* NORMALIZE INTO THE DESCRIPTOR'S FRAME (2026-08-16).
+                                 * This copied the RAW vector, but engram_geometry
+                                 * builds every descriptor over L2-normalized member
+                                 * embeddings, so the anchor was being fitted against
+                                 * an ellipsoid at a radius it was never fitted over.
+                                 * Measured on the self region: magnitude 0.00283443
+                                 * raw vs 0.521837 in-frame on the same pair — a 180x
+                                 * error, and the reason every fit score sat three
+                                 * decimal places below the 0.5 floors that gate on
+                                 * them. The frame contract is stated in
+                                 * engram_verify.h; this call site did not honour it.
+                                 * Idempotent when the stored vector is already unit. */
                                 anchor = malloc(sizeof(float) * (size_t)g->dim);
-                                if (anchor) memcpy(anchor, n->emb,
-                                                   sizeof(float) * (size_t)g->dim);
+                                if (anchor) {
+                                    double s2 = 0;
+                                    for (int i = 0; i < g->dim; i++)
+                                        s2 += (double)n->emb[i] * (double)n->emb[i];
+                                    double nn = sqrt(s2);
+                                    if (nn > 1e-12)
+                                        for (int i = 0; i < g->dim; i++)
+                                            anchor[i] = (float)((double)n->emb[i] / nn);
+                                    else
+                                        memcpy(anchor, n->emb, sizeof(float) * (size_t)g->dim);
+                                }
                             }
                         }
                         free(id);
@@ -14366,88 +14475,522 @@ el_val_t engram_think_json(el_val_t seeds, el_val_t faculty) {
     return el_wrap_str(b.buf);
 }
 
-/* engram_ground_json(claim_csv, evidence_csv, for_whom) — grounding as a RELATION.
- * Turns the DORMANT verifier inward for real: verifies the claim region's centroid
- * against the evidence region, then writes a grounded-by edge (weight = grounding,
- * grounded-for-whom). Additive. */
+/* ═══════════════════════════════════════════════════════════════════════════
+ * §7 WIRING — GROUNDING IS THE EDGE'S WEIGHT, AND THE WEIGHT IS A VECTOR
+ * (2026-08-16; spec correspondence-and-censorship.md @ 2b7e4ba.)
+ *
+ * What was here minted a `grounded-by` edge on every call and returned a float.
+ * Every part of that was wrong, and #147 only fixed the endpoints:
+ *   - grounding is a property OF a relation, not a relation BETWEEN nodes, so
+ *     there was nothing for a new edge to carry;
+ *   - the call was a READ that wrote — the eg_vindex_sync defect;
+ *   - one scalar cannot separate "true and meaningful" from "true and misapplied",
+ *     nor "no support" from "actively contradicts".
+ *
+ * ground() is now pure: it reads the vector the RELATION already carries, decays
+ * it analytically to now on the runtime's one decay model, computes what the
+ * current geometry would say, and reports whether that move is consequential —
+ * without recording it. Recording is a separate, explicitly named write.
+ * ═══════════════════════════════════════════════════════════════════════════ */
+
+/* The values reference: THIRTEEN regions, discovered from the graph rather than
+ * hardcoded, so a fourteenth value is picked up without a code change. They are
+ * the nodes the values root `contains`. Measured on the live store: exactly 13,
+ * pairwise centroid cosine min 0.1525 / mean 0.5199 / max 0.9278 — not one region. */
+#define EG_VALUES_ROOT_DEFAULT "kn-5b606390-a52d-4ca2-8e0e-eba141d13440"
+#define EG_MAX_VALUES 32
+typedef struct {
+    int   n;
+    char* ids[EG_MAX_VALUES];
+    GeoDescriptor* g[EG_MAX_VALUES];
+} EgValueRef;
+
+static void eg_values_release(EgValueRef* v) {
+    if (!v) return;
+    for (int i = 0; i < v->n; i++) { free(v->ids[i]); if (v->g[i]) engram_geo_free(v->g[i]); }
+    v->n = 0;
+}
+static int eg_values_build(EgValueRef* out) {
+    if (!out || !g_engram_store) return -1;
+    memset(out, 0, sizeof *out);
+    const char* root = getenv("ENGRAM_VALUES_ROOT");
+    if (!root || !*root) root = EG_VALUES_ROOT_DEFAULT;
+    StoreEdge* edges = NULL; size_t ne = 0;
+    if (store_get_edges_from(g_engram_store, root, &edges, &ne) < 0) return -1;
+    for (size_t i = 0; i < ne && out->n < EG_MAX_VALUES; i++) {
+        if (edges[i].tombstoned) continue;
+        if (!edges[i].relation || strcmp(edges[i].relation, "contains") != 0) continue;
+        if (!edges[i].to_id) continue;
+        GeoDescriptor* g = eg_geo_build_desc(edges[i].to_id);
+        if (!g) continue;
+        out->ids[out->n] = strdup(edges[i].to_id);
+        out->g[out->n]   = g;
+        out->n++;
+    }
+    store_edges_free(edges, ne);
+    return out->n;
+}
+
+/* THE REFERENCE FRAME IS BUILT ONCE AND HELD. Two reasons, and the second is the
+ * real one:
+ *   - cost: thirteen descriptors over the whole node vector per call made a
+ *     single /api/ground take tens of seconds;
+ *   - correctness: a reference frame that is rebuilt on every read moves under
+ *     the measurement, which is the defect the whole spec is about. Holding it
+ *     for the process lifetime is the closest this layer can come to "the frame
+ *     updates when it is not being used to act" without owning that decision —
+ *     which belongs to the dreamer, not here. ENGRAM_VALUES_NOCACHE=1 forces a
+ *     rebuild per call for tests that deliberately move a value node. */
+static EgValueRef _eg_values_cache;
+static int        _eg_values_cached = 0;
+static const EgValueRef* eg_values_ref(void) {
+    const char* nc = getenv("ENGRAM_VALUES_NOCACHE");
+    if (nc && nc[0] && nc[0] != '0') {
+        if (_eg_values_cached) { eg_values_release(&_eg_values_cache); _eg_values_cached = 0; }
+    }
+    if (!_eg_values_cached) {
+        if (eg_values_build(&_eg_values_cache) <= 0) return NULL;
+        _eg_values_cached = 1;
+    }
+    return &_eg_values_cache;
+}
+
+/* Copy a node's embedding INTO THE DESCRIPTOR'S FRAME (never borrow — g->nodes is
+ * realloc'd on append, so a borrowed EngramNode* dangles across any concurrent write).
+ *
+ * THE FRAME CONTRACT IS LOAD-BEARING AND WAS BEING VIOLATED. engram_verify.h states
+ * it plainly: the claim point and the descriptor must share the same frame.
+ * engram_geometry builds every descriptor over L2-NORMALIZED member embeddings —
+ * `centroid` is the mean of normcopy()'d vectors and the principal axes are computed
+ * against that — while the raw `n->emb` in the resident store is not necessarily unit.
+ * Fitting a raw vector against a unit-frame descriptor puts the point at a radius the
+ * ellipsoid was never fitted over, so the distance is dominated by the norm mismatch
+ * and every fit score collapses toward zero. Normalizing here is idempotent when the
+ * stored vector is already unit, so it can only help. */
+static float* eg_node_emb_copy(const char* id, int dim) {
+    EngramStore* eg = engram_get();
+    if (!eg || !id || dim <= 0) return NULL;
+    int64_t idx = engram_find_node_index(id);
+    if (idx < 0 || idx >= eg->node_count) return NULL;
+    EngramNode* n = &eg->nodes[idx];
+    if (!n->emb || n->emb_dim != dim) return NULL;
+    float* p = malloc(sizeof(float) * (size_t)dim);
+    if (!p) return NULL;
+    double s = 0;
+    for (int i = 0; i < dim; i++) s += (double)n->emb[i] * (double)n->emb[i];
+    double nn = sqrt(s);
+    if (nn > 1e-12) for (int i = 0; i < dim; i++) p[i] = (float)((double)n->emb[i] / nn);
+    else            memcpy(p, n->emb, sizeof(float) * (size_t)dim);
+    return p;
+}
+/* Salience of a relation = the salience of its endpoints, reusing the fields the
+ * runtime already keeps (node salience and working-memory weight). Consolidation
+ * is gated by salience — that is why you remember the argument and not the
+ * commute — and this deliberately reads existing state rather than introducing a
+ * threshold of its own. */
+static double eg_node_salience(const char* id) {
+    EngramStore* eg = engram_get();
+    if (!eg || !id) return 0.0;
+    int64_t idx = engram_find_node_index(id);
+    if (idx < 0 || idx >= eg->node_count) return 0.0;
+    EngramNode* n = &eg->nodes[idx];
+    double s = n->salience;
+    if (n->working_memory_weight > s) s = n->working_memory_weight;
+    if (n->background_activation > s) s = n->background_activation;
+    return s;
+}
+static double eg_vdot(const float* a, const float* b, int dim) {
+    double s = 0; for (int i = 0; i < dim; i++) s += (double)a[i] * (double)b[i]; return s;
+}
+/* Signed projection of a unit gradient onto unit(target − x): positive means the
+ * descent direction still points toward the target. Frame-independent, so it
+ * stays comparable across versions even if the region's principal axes rotate —
+ * which is what makes the DIRECTION_REVERSAL test meaningful over time. */
+static double eg_proj_toward(const float* dir, const float* x, const float* target, int dim) {
+    double s = 0, n2 = 0;
+    for (int i = 0; i < dim; i++) { double d = (double)target[i] - (double)x[i]; s += (double)dir[i] * d; n2 += d * d; }
+    double n = sqrt(n2);
+    return n > 1e-12 ? s / n : 0.0;
+}
+
+/* RELATIONAL grounding of a point: the MIN fit over the thirteen value regions,
+ * and the NAME of the value that binds. Min, not mean, because a mean lets strong
+ * agreement with twelve values mask a violation of the thirteenth — which is the
+ * mechanism of rationalization, not a scoring detail. */
+static int eg_relational_read(const float* x, const EgValueRef* V,
+                              double* out_score, int* out_idx, float** out_dir) {
+    if (!x || !V || V->n <= 0) return -1;
+    double worst = 2.0; int wi = -1;
+    for (int i = 0; i < V->n; i++) {
+        GeoFit f;
+        if (cog_warped_fit(V->g[i], x, NULL, &f) != 0) continue;
+        if (f.score < worst) { worst = f.score; wi = i; }
+    }
+    if (wi < 0) return -1;
+    if (out_score) *out_score = worst;
+    if (out_idx)   *out_idx   = wi;
+    if (out_dir) {
+        GeoGradient gr;
+        if (engram_think(V->g[wi], x, NULL, &gr) == 0) {
+            *out_dir = gr.direction; gr.direction = NULL;   /* take ownership */
+            engram_gradient_free(&gr);
+        } else *out_dir = NULL;
+    }
+    return 0;
+}
+
+/* Find the live relation between two nodes, in either orientation, and return
+ * the NEWEST recorded version of it. Returns 1 on hit. */
+static int eg_find_relation(const char* a, const char* b, StoreEdge* out, char* base_id, size_t cap) {
+    if (!g_engram_store || !a || !b) return 0;
+    for (int dir = 0; dir < 2; dir++) {
+        const char* from = dir == 0 ? a : b;
+        const char* to   = dir == 0 ? b : a;
+        StoreEdge* edges = NULL; size_t ne = 0;
+        if (store_get_edges_from(g_engram_store, from, &edges, &ne) < 0) continue;
+        for (size_t i = 0; i < ne; i++) {
+            if (edges[i].tombstoned) continue;
+            if (!edges[i].to_id || strcmp(edges[i].to_id, to) != 0) continue;
+            if (edges[i].id && strchr(edges[i].id, '#')) continue;  /* a version, not a root */
+            snprintf(base_id, cap, "%s", edges[i].id ? edges[i].id : "");
+            store_edges_free(edges, ne);
+            if (cog_grounding_head(g_engram_store, base_id, out, 64) >= 0) return 1;
+            return 0;
+        }
+        store_edges_free(edges, ne);
+    }
+    return 0;
+}
+
+/* The two-axis observation of one relation from the CURRENT geometry. Pure.
+ * factual   = how well the far endpoint sits in the near endpoint's neighbourhood
+ *             — a real correspondence measurement of the relation itself;
+ * relational = min fit over the thirteen value regions, with the binding name;
+ * cos_angle  = the cosine between the two full-dimensional gradients. */
+typedef struct {
+    int    ok;
+    double factual, relational, cos_angle, fac_proj, rel_proj;
+    char   binding[128];
+} EgObservation;
+
+static int eg_observe_relation(const char* from_id, const char* to_id,
+                               const EgValueRef* V, EgObservation* out) {
+    memset(out, 0, sizeof *out);
+    GeoDescriptor* R = eg_geo_build_desc(from_id);
+    if (!R) return -1;
+    int dim = R->dim;
+    float* x = eg_node_emb_copy(to_id, dim);
+    if (!x) { engram_geo_free(R); return -1; }
+
+    GeoFit f;
+    if (cog_warped_fit(R, x, NULL, &f) != 0) { free(x); engram_geo_free(R); return -1; }
+    out->factual = f.score;
+
+    GeoGradient fg;
+    float* fac_dir = NULL;
+    if (engram_think(R, x, NULL, &fg) == 0) { fac_dir = fg.direction; fg.direction = NULL; engram_gradient_free(&fg); }
+
+    int vi = -1; float* rel_dir = NULL;
+    if (eg_relational_read(x, V, &out->relational, &vi, &rel_dir) == 0 && vi >= 0)
+        snprintf(out->binding, sizeof out->binding, "%s", V->ids[vi]);
+
+    if (fac_dir && R->centroid) out->fac_proj = eg_proj_toward(fac_dir, x, R->centroid, dim);
+    if (rel_dir && vi >= 0 && V->g[vi]->centroid) out->rel_proj = eg_proj_toward(rel_dir, x, V->g[vi]->centroid, dim);
+    if (fac_dir && rel_dir) out->cos_angle = eg_vdot(fac_dir, rel_dir, dim);
+
+    free(fac_dir); free(rel_dir); free(x); engram_geo_free(R);
+    out->ok = 1;
+    return 0;
+}
+
+/* Fold an observation into the vector as it would stand now. The accrual is a
+ * running MEAN over reinforcements — the same form the beat's calibration
+ * already uses (brier_sum / n_trials) — so no rate constant is introduced. */
+static void eg_fold_observation(const CogGrounding* prev, const EgObservation* obs,
+                                CogProvClass prov, double floor, double rel_floor,
+                                int64_t now, CogGrounding* out) {
+    *out = *prev;
+    double n = prev->reinforcements;
+    out->factual    = prev->present ? prev->factual    + (obs->factual    - prev->factual)    / (n + 1.0) : obs->factual;
+    out->relational = prev->present ? prev->relational + (obs->relational - prev->relational) / (n + 1.0) : obs->relational;
+    out->fac_proj = obs->fac_proj; out->rel_proj = obs->rel_proj; out->cos_angle = obs->cos_angle;
+    out->agreement = obs->cos_angle > 0 ? 1 : (obs->cos_angle < 0 ? -1 : 0);
+    out->reinforcements = n + 1.0;
+    out->ts = now;
+    if (prov != COG_PROV_UNSET) out->prov = prov;
+    out->floor_at_record = floor; out->rel_floor_at_record = rel_floor;
+    snprintf(out->binding_value, sizeof out->binding_value, "%s", obs->binding);
+    /* DERIVED, recomputed at the instant — never carried over from prev. */
+    out->age_ms = 0; out->decay = 1.0;
+    out->factual_now = out->factual; out->relational_now = out->relational;
+    out->associative_now = out->associative;
+    out->stale = 0;
+}
+
+static void eg_emit_vector(JsonBuf* b, const char* key, const CogGrounding* g) {
+    char t[768];
+    snprintf(t, sizeof t,
+        "\"%s\":{\"established\":%s,"
+        "\"factual\":%.6g,\"relational\":%.6g,\"associative\":%.6g,\"polarity\":%.6g,"
+        "\"provenance\":\"%s\",\"ts\":%lld,\"seq\":%lld,\"reinforcements\":%.6g,"
+        "\"cos_angle\":%.6g,\"agreement\":%d,\"fac_proj\":%.6g,\"rel_proj\":%.6g,"
+        "\"binding_value\":\"%s\","
+        "\"derived\":{\"age_s\":%lld,\"decay\":%.6g,\"factual_now\":%.6g,"
+        "\"relational_now\":%.6g,\"associative_now\":%.6g,\"stale\":%s}}",
+        key, g->present ? "true" : "false",
+        g->factual, g->relational, g->associative, g->polarity,
+        cog_prov_name(g->prov), (long long)g->ts, (long long)g->seq, g->reinforcements,
+        g->cos_angle, g->agreement, g->fac_proj, g->rel_proj,
+        g->binding_value[0] ? g->binding_value : "-",
+        (long long)(g->age_ms / 1000), g->decay, g->factual_now,
+        g->relational_now, g->associative_now, g->stale ? "true" : "false");
+    jb_puts(b, t);
+}
+
+/* engram_ground_json(claim, evidence, for_whom) — a READ. Never writes. */
 el_val_t engram_ground_json(el_val_t claim, el_val_t evidence, el_val_t for_whom) {
     if (!g_engram_store) return eg_geo_err("store unavailable");
-    GeoDescriptor* C = eg_geo_build_desc(EL_CSTR(claim));
-    GeoDescriptor* E = eg_geo_build_desc(EL_CSTR(evidence));
-    if (!C || !E) { if (C) engram_geo_free(C); if (E) engram_geo_free(E); return eg_geo_err("geometry unavailable"); }
-    const GeoDescriptor* ev[1] = { E };
-    GeoGrounding gr;
-    int rc = engram_verify_grounding(C->centroid, C->dim, ev, 1, 1.0, 0.5, &gr);
-    double grounding = (rc == 0) ? gr.grounding : 0.0;
-    if (rc == 0) engram_verify_grounding_free(&gr);
-    const char* fw = EL_CSTR(for_whom); if (fw && !*fw) fw = NULL;
-
-    /* GROUND THE NODE ASKED ABOUT, AND SAY WHAT WAS RESOLVED (2026-08-16
-     * self-review). This wrote the grounded-by edge between the two REGION
-     * HUBS and then echoed those hubs back in the "claim"/"evidence" fields
-     * as though they were the caller's input. Three consequences, all measured
-     * against the live store:
-     *
-     *  1. The edge landed on a node the caller never named. Asking to ground
-     *     3b9ced5d against 6edf8c79 wrote an edge on 6edf8c79 -> d0406dfd,
-     *     because those were the hubs of the two regions.
-     *  2. When both seeds resolve into the same region, the hubs coincide and
-     *     the call grounds a node against ITSELF, returning grounding = 1 —
-     *     a perfect score with no evidence behind it. Two independent agents
-     *     hit this and reported 0.885 / 0.909 self-groundings as confident.
-     *  3. The echo concealed both, because the response looked exactly like a
-     *     successful grounding of the ids that were passed in.
-     *
-     * The region is HOW a claim is evaluated; it is not WHAT the claim is
-     * about. So the edge attaches to the requested ids, and the resolved hubs
-     * are reported separately under claim_region / evidence_region. When the
-     * two regions coincide, the grounding is degenerate by construction and is
-     * reported as such rather than as a confident 1.0. */
     const char* cid = EL_CSTR(claim);
     const char* eid = EL_CSTR(evidence);
-    const char* chub = C->hub_id ? C->hub_id : cid;
-    const char* ehub = E->hub_id ? E->hub_id : eid;
-    /* Degeneracy is broader than chub == ehub. Three circular shapes, each of
-     * which yields a high score for structural reasons rather than evidential
-     * ones, and all three were previously invisible:
-     *   same-region   both seeds resolve to one region — grounding a thing
-     *                 against itself.
-     *   claim-in-ev   the claim's region hub IS the evidence node: the evidence
-     *                 sits at the centre of the claim's own neighbourhood.
-     *   ev-in-claim   the mirror case.
-     * Measured: grounding 3b9ced5d against 6edf8c79 scored 0.98883 purely
-     * because 6edf8c79 is the hub of 3b9ced5d's region. */
-    const char* degenerate = NULL;
-    if (chub && ehub && strcmp(chub, ehub) == 0)            degenerate = "same-region";
-    else if (chub && eid && strcmp(chub, eid) == 0)         degenerate = "claim-region-is-evidence";
-    else if (ehub && cid && strcmp(ehub, cid) == 0)         degenerate = "evidence-region-is-claim";
-    if (degenerate) grounding = 0.0;   /* circular support is not support */
+    const char* fw  = EL_CSTR(for_whom); if (fw && !*fw) fw = NULL;
+    int64_t now = engram_now_ms();
 
-    /* Do not write an edge for a grounding that is degenerate by construction. */
-    int wr = degenerate ? -1 : cog_ground_edge(g_engram_store, cid, eid, grounding, fw);
-    JsonBuf b; jb_init(&b); char t[512];
-    snprintf(t, sizeof t, "{\"relation\":\"grounded-by\",\"claim\":\"%s\",\"evidence\":\"%s\","
-             "\"claim_region\":\"%s\",\"evidence_region\":\"%s\",\"degenerate\":%s%s%s,"
-             "\"for_whom\":\"%s\",\"grounding\":%.6g,\"written\":%s}",
-             cid ? cid : "", eid ? eid : "", chub ? chub : "", ehub ? ehub : "",
-             degenerate ? "\"" : "false", degenerate ? degenerate : "", degenerate ? "\"" : "",
-             fw ? fw : "-", grounding, wr == 0 ? "true" : "false");
+    StoreEdge cur; char base_id[192] = "";
+    JsonBuf b; jb_init(&b); char t[768];
+
+    if (!eg_find_relation(cid, eid, &cur, base_id, sizeof base_id)) {
+        /* THE HONEST ANSWER. There is nothing to ground a claim "against" that is
+         * not already a relation. This previously minted one and scored it — and
+         * when both seeds fell in one region the score came back 1.0 with no
+         * evidence behind it. If the two are unrelated, say so and write nothing. */
+        snprintf(t, sizeof t,
+            "{\"claim\":\"%s\",\"evidence\":\"%s\",\"for_whom\":\"%s\",\"related\":false,"
+            "\"grounding\":null,\"written\":false,"
+            "\"note\":\"no relation between these nodes; grounding is a property of a relation, not a score minted between nodes\"}",
+            cid ? cid : "", eid ? eid : "", fw ? fw : "-");
+        jb_puts(&b, t);
+        return el_wrap_str(b.buf);
+    }
+
+    CogGrounding rec; cog_grounding_parse(&cur, now, &rec);
+
+    const EgValueRef* V = eg_values_ref();
+    EgObservation obs; memset(&obs, 0, sizeof obs);
+    int nv = V ? V->n : 0;
+    if (nv > 0 && cur.from_id && cur.to_id) eg_observe_relation(cur.from_id, cur.to_id, V, &obs);
+
+    double floor = 0.5, rel_floor = 0.5;
+    CogGrounding ng = rec;
+    if (obs.ok) eg_fold_observation(&rec, &obs, COG_PROV_UNSET, floor, rel_floor, now, &ng);
+    CogSignificance sig = obs.ok ? cog_grounding_significant(&rec, &ng, floor, rel_floor)
+                                 : COG_SIG_NONE;
+    double sal = cur.from_id && cur.to_id
+               ? (eg_node_salience(cur.from_id) > eg_node_salience(cur.to_id)
+                  ? eg_node_salience(cur.from_id) : eg_node_salience(cur.to_id))
+               : 0.0;
+
+    CogTrajectory tr; memset(&tr, 0, sizeof tr);
+    cog_grounding_trajectory(g_engram_store, base_id, now, &tr);
+
+    jb_putc(&b, '{');
+    snprintf(t, sizeof t,
+        "\"claim\":\"%s\",\"evidence\":\"%s\",\"for_whom\":\"%s\",\"related\":true,"
+        "\"relation\":\"%s\",\"edge\":\"%s\",\"edge_root\":\"%s\",\"from\":\"%s\",\"to\":\"%s\","
+        "\"value_regions\":%d,\"aggregate\":\"min\",\"salience\":%.6g,",
+        cid ? cid : "", eid ? eid : "", fw ? fw : "-",
+        cur.relation ? cur.relation : "", cur.id ? cur.id : "", base_id,
+        cur.from_id ? cur.from_id : "", cur.to_id ? cur.to_id : "", nv > 0 ? nv : 0, sal);
     jb_puts(&b, t);
-    engram_geo_free(C); engram_geo_free(E);
+    eg_emit_vector(&b, "recorded", &rec);
+    jb_putc(&b, ',');
+    if (obs.ok) eg_emit_vector(&b, "observed", &ng);
+    else        jb_puts(&b, "\"observed\":null");
+    /* Volatility and drift are computed here and stored nowhere — the series
+     * exists only because nothing was destroyed. */
+    snprintf(t, sizeof t,
+        ",\"trajectory\":{\"n_versions\":%d,\"factual_volatility\":%.6g,"
+        "\"relational_volatility\":%.6g,\"factual_drift\":%.6g,\"relational_drift\":%.6g,"
+        "\"stayed_true_became_wrong\":%s}"
+        ",\"would_record\":%s,\"significance\":\"%s\",\"inherent\":%s,\"written\":false}",
+        tr.n_versions, tr.factual_volatility, tr.relational_volatility,
+        tr.factual_drift, tr.relational_drift,
+        tr.stayed_true_became_wrong ? "true" : "false",
+        sig != COG_SIG_NONE ? "true" : "false", cog_significance_name(sig),
+        cog_significance_inherent(sig) ? "true" : "false");
+    jb_puts(&b, t);
+
+    store_edge_free(&cur);
     return el_wrap_str(b.buf);
 }
 
-/* engram_assert_json(claim_id, for_whom, floor) — the honesty floor as a QUERY at
- * ASSERTION time only (holding is never gated). Reads the claim's grounded-by
- * edges (for the observer) and returns whether assertion is permitted. */
-el_val_t engram_assert_json(el_val_t claim_id, el_val_t for_whom, el_val_t floor) {
+/* engram_ground_record_json — the WRITE half, named as one. Recomputes the
+ * vector, applies the consolidation gate (salience + per-dimension consequence),
+ * and on significance supersedes the EDGE, versioning the WHOLE vector jointly.
+ * The predecessor is never touched.
+ *
+ * There is no provenance predicate here and nothing takes its place. An earlier
+ * pass built one — a bounded traversal over a grounding-chain graph, refusing
+ * evidence downstream of the region being calibrated. It is deleted. Circularity
+ * of the reference frame is TEMPORAL, not topological: you cannot recalibrate the
+ * ruler while measuring with it, so that update happens when the frame is not
+ * being used to act, which is a fact about engagement and belongs to the dreamer.
+ * The measurement that settles it: reachability from the self region reaches
+ * 89.2% of the live graph, so any topological predicate marks nearly all evidence
+ * tainted and degenerates into the total block censorship started as. */
+el_val_t engram_ground_record_json(el_val_t claim, el_val_t evidence,
+                                   el_val_t provenance, el_val_t floor_v) {
+    if (!g_engram_store) return eg_geo_err("store unavailable");
+    const char* cid = EL_CSTR(claim);
+    const char* eid = EL_CSTR(evidence);
+    double floor = atof(EL_CSTR(floor_v)); if (!(floor > 0)) floor = 0.5;
+    double rel_floor = floor;
+    CogProvClass prov = cog_prov_parse(EL_CSTR(provenance));
+    int64_t now = engram_now_ms();
+
+    StoreEdge cur; char base_id[192] = "";
+    JsonBuf b; jb_init(&b); char t[768];
+    if (!eg_find_relation(cid, eid, &cur, base_id, sizeof base_id)) {
+        snprintf(t, sizeof t, "{\"claim\":\"%s\",\"evidence\":\"%s\",\"related\":false,\"written\":false}",
+                 cid ? cid : "", eid ? eid : "");
+        jb_puts(&b, t); return el_wrap_str(b.buf);
+    }
+
+    CogGrounding rec; cog_grounding_parse(&cur, now, &rec);
+    const EgValueRef* V = eg_values_ref();
+    EgObservation obs; memset(&obs, 0, sizeof obs);
+    int nv = V ? V->n : 0;
+    if (nv <= 0 || !cur.from_id || !cur.to_id ||
+        eg_observe_relation(cur.from_id, cur.to_id, V, &obs) != 0 || !obs.ok) {
+        store_edge_free(&cur);
+        return eg_geo_err("geometry unavailable for this relation");
+    }
+
+    CogGrounding ng;
+    eg_fold_observation(&rec, &obs, prov, floor, rel_floor, now, &ng);
+
+    CogSignificance sig = cog_grounding_significant(&rec, &ng, floor, rel_floor);
+    /* CONSOLIDATION GATE. Significance says the move would change a decision;
+     * salience says it is worth making durable. The two INHERENT moves — a
+     * polarity sign flip and a provenance class change — bypass salience because
+     * they are discrete changes of state rather than drift. */
+    double sal = eg_node_salience(cur.from_id) > eg_node_salience(cur.to_id)
+               ? eg_node_salience(cur.from_id) : eg_node_salience(cur.to_id);
+    int salient = (sal > 0.0);
+    int consolidate = (sig != COG_SIG_NONE) && (cog_significance_inherent(sig) || salient);
+
+    char written_id[224] = "";
+    int seq = -1;
+    if (consolidate) seq = cog_grounding_record(g_engram_store, &cur, &ng, written_id, sizeof written_id);
+
+    jb_putc(&b, '{');
+    snprintf(t, sizeof t,
+        "\"claim\":\"%s\",\"evidence\":\"%s\",\"edge\":\"%s\",\"edge_root\":\"%s\","
+        "\"value_regions\":%d,\"aggregate\":\"min\",\"floor\":%.4g,\"rel_floor\":%.4g,"
+        "\"salience\":%.6g,\"salient\":%s,",
+        cid ? cid : "", eid ? eid : "", cur.id ? cur.id : "", base_id,
+        nv, floor, rel_floor, sal, salient ? "true" : "false");
+    jb_puts(&b, t);
+    eg_emit_vector(&b, "previous", &rec); jb_putc(&b, ',');
+    eg_emit_vector(&b, "observed", &ng);
+    snprintf(t, sizeof t,
+        ",\"significance\":\"%s\",\"inherent\":%s,\"consolidated\":%s,"
+        "\"written\":%s,\"version\":%d,\"version_id\":\"%s\"}",
+        cog_significance_name(sig), cog_significance_inherent(sig) ? "true" : "false",
+        consolidate ? "true" : "false",
+        (consolidate && seq > 0) ? "true" : "false", seq > 0 ? seq : 0, written_id);
+    jb_puts(&b, t);
+
+    store_edge_free(&cur);
+    return el_wrap_str(b.buf);
+}
+
+/* engram_ground_trajectory_json(claim, evidence) — the supersession chain read as
+ * a TIME SERIES OF VECTORS. Not only what the grounding is but which way it has
+ * been moving and how fast — a derivative obtained for free from immutability,
+ * because the points were never destroyed. */
+el_val_t engram_ground_trajectory_json(el_val_t claim, el_val_t evidence) {
+    if (!g_engram_store) return eg_geo_err("store unavailable");
+    StoreEdge cur; char base_id[192] = "";
+    if (!eg_find_relation(EL_CSTR(claim), EL_CSTR(evidence), &cur, base_id, sizeof base_id))
+        return eg_geo_err("no relation between these nodes");
+    store_edge_free(&cur);
+    int64_t now = engram_now_ms();
+    JsonBuf b; jb_init(&b); char t[768];
+    jb_puts(&b, "{\"edge_root\":\""); jb_puts(&b, base_id); jb_puts(&b, "\",\"versions\":[");
+    int emitted = 0;
+    for (int v = 0; v <= 64; v++) {
+        char vid[224];
+        if (v == 0) snprintf(vid, sizeof vid, "%s", base_id);
+        else        snprintf(vid, sizeof vid, "%s#%d", base_id, v);
+        StoreEdge e;
+        if (store_get_edge(g_engram_store, vid, &e) != 1) { if (v) break; else continue; }
+        CogGrounding g; cog_grounding_parse(&e, now, &g);
+        if (emitted) jb_putc(&b, ',');
+        snprintf(t, sizeof t,
+            "{\"version\":%d,\"id\":\"%s\",\"established\":%s,\"ts\":%lld,"
+            "\"factual\":%.6g,\"relational\":%.6g,\"associative\":%.6g,\"polarity\":%.6g,"
+            "\"provenance\":\"%s\",\"cos_angle\":%.6g,\"agreement\":%d,"
+            "\"binding_value\":\"%s\",\"prev\":\"%s\","
+            "\"derived\":{\"age_s\":%lld,\"decay\":%.6g,\"factual_now\":%.6g,\"stale\":%s}}",
+            v, vid, g.present ? "true" : "false", (long long)g.ts,
+            g.factual, g.relational, g.associative, g.polarity,
+            cog_prov_name(g.prov), g.cos_angle, g.agreement,
+            g.binding_value[0] ? g.binding_value : "-", g.prev_edge,
+            (long long)(g.age_ms / 1000), g.decay, g.factual_now, g.stale ? "true" : "false");
+        jb_puts(&b, t); emitted++;
+        store_edge_free(&e);
+    }
+    CogTrajectory tr; memset(&tr, 0, sizeof tr);
+    cog_grounding_trajectory(g_engram_store, base_id, now, &tr);
+    snprintf(t, sizeof t,
+        "],\"n_versions\":%d,\"derived\":{\"factual_volatility\":%.6g,"
+        "\"relational_volatility\":%.6g,\"factual_drift\":%.6g,\"relational_drift\":%.6g,"
+        "\"stayed_true_became_wrong\":%s}}",
+        emitted, tr.factual_volatility, tr.relational_volatility,
+        tr.factual_drift, tr.relational_drift,
+        tr.stayed_true_became_wrong ? "true" : "false");
+    jb_puts(&b, t);
+    return el_wrap_str(b.buf);
+}
+
+/* engram_assert_json(claim_id, for_whom, floor, rel_floor) — the honesty floor as
+ * a QUERY at ASSERTION time only (holding is never gated), now gating on BOTH
+ * axes. A well-evidenced claim must not earn the right to be asserted regardless
+ * of whether it means the right thing.
+ *
+ * `still_held` was a HARDCODED `true` in this format string — a temporal property
+ * named in the API and answered without consulting anything, which is invariant
+ * §8.1 violated in one literal. It is now derived: the claim's node is read and
+ * the field reports whether the content is present and live. Holding remains
+ * unconditional; what decays is the GROUNDING, and a relation whose decayed
+ * grounding has fallen below its floor stops being assertable on its own,
+ * without anyone having to remember to check. */
+el_val_t engram_assert_json(el_val_t claim_id, el_val_t for_whom, el_val_t floor, el_val_t rel_floor) {
     if (!g_engram_store) return eg_geo_err("store unavailable");
     const char* fw = EL_CSTR(for_whom); if (fw && !*fw) fw = NULL;
-    double fl = atof(EL_CSTR(floor)); if (!(fl > 0)) fl = 0.5;
-    int gate = cog_assert_gate(g_engram_store, EL_CSTR(claim_id), fw, fl);
-    JsonBuf b; jb_init(&b); char t[192];
-    snprintf(t, sizeof t, "{\"claim\":\"%s\",\"for_whom\":\"%s\",\"floor\":%.4g,\"may_assert\":%s,\"still_held\":true}",
-             EL_CSTR(claim_id), fw ? fw : "-", fl, gate == 1 ? "true" : "false");
+    double fl  = atof(EL_CSTR(floor));     if (!(fl > 0))  fl = 0.5;
+    double rfl = atof(EL_CSTR(rel_floor)); if (!(rfl > 0)) rfl = fl;
+    CogAssertion a;
+    if (cog_assert_two_axis(g_engram_store, EL_CSTR(claim_id), fl, rfl, engram_now_ms(), &a) != 0)
+        return eg_geo_err("assert failed");
+    JsonBuf b; jb_init(&b); char t[640];
+    snprintf(t, sizeof t,
+        "{\"claim\":\"%s\",\"for_whom\":\"%s\",\"floor\":%.4g,\"rel_floor\":%.4g,"
+        "\"may_assert\":%s,\"still_held\":%s,\"found\":%s,\"n_relations\":%d,"
+        "\"factual\":%.6g,\"relational\":%.6g,\"relational_established\":%s,"
+        "\"cos_angle\":%.6g,\"agreement\":%d,\"binding_value\":\"%s\",\"best_relation\":\"%s\","
+        "\"refused_because\":\"%s\"}",
+        EL_CSTR(claim_id), fw ? fw : "-", fl, rfl,
+        a.may_assert ? "true" : "false", a.still_held ? "true" : "false",
+        a.found ? "true" : "false", a.n_edges,
+        a.factual, a.relational, a.relational_established ? "true" : "false",
+        a.cos_angle, a.agreement,
+        a.binding_value[0] ? a.binding_value : "-", a.best_edge,
+        a.may_assert                  ? "-" :
+        !a.found                      ? "no-relation" :
+        !a.relational_established     ? "relational-axis-never-established" :
+        (a.factual    < fl)           ? "below-factual-floor" :
+        (a.relational < rfl)          ? "below-relational-floor" : "-");
     jb_puts(&b, t);
     return el_wrap_str(b.buf);
 }
@@ -14547,15 +15090,22 @@ el_val_t engram_correspondence_beat_json(el_val_t seeds, el_val_t faculty, el_va
     JsonBuf b; jb_init(&b); char t[384];
     snprintf(t, sizeof t,
       "{\"faculty\":\"%s\",\"stance_id\":\"%s\",\"region_hub\":\"%s\",\"dim\":%d,\"n_axes\":%d,\"signal_axes\":%d,"
+      /* `keystone_write_blocked` is GONE from this response. It reported that the
+       * beat had refused to learn about the reference frame, and the measured
+       * cost of that refusal was 0.00% brier reduction over n_trials 0 on the
+       * keystone region — the loop never ran, so nothing about the self was ever
+       * calibrated OR falsifiable. Nothing replaces the flag: non-circularity of
+       * the reference frame is temporal, not a permission (spec §5.2). The
+       * `keystone` field is retained as a label on the region, and it no longer
+       * gates anything. */
       "\"resumed\":%s,\"keystone\":%s,\"probes\":%d,\"epochs\":%d,"
       "\"brier_before\":%.6g,\"brier_after\":%.6g,\"reduction_pct\":%.2f,"
-      "\"reliability\":%.6g,\"n_trials\":%lld,\"stance_written\":%s,\"keystone_write_blocked\":%s}",
+      "\"reliability\":%.6g,\"n_trials\":%lld,\"stance_written\":%s}",
       EL_CSTR(faculty), sid, g->hub_id ? g->hub_id : "region", dim, na, signal,
       resumed ? "true" : "false", st.keystone ? "true" : "false", NP, EP,
       brier_before, brier_after,
       brier_before > 0 ? 100.0 * (brier_before - brier_after) / brier_before : 0.0,
-      st.reliability, (long long)st.n_trials, wrote == 0 ? "true" : "false",
-      st.keystone ? "true" : "false");
+      st.reliability, (long long)st.n_trials, wrote == 0 ? "true" : "false");
     jb_puts(&b, t);
     cog_stance_free(&st); engram_geo_free(g);
     return el_wrap_str(b.buf);

lang/runtime/el_runtime.h

@@ -666,6 +666,10 @@ el_val_t  engram_get_node(el_val_t id);
 void      engram_strengthen(el_val_t node_id);
 void      engram_forget(el_val_t node_id);
 el_val_t  engram_prune_telemetry(el_val_t older_than_ms);
+/* Largest byte length <= max_bytes that does not split a UTF-8 codepoint.
+ * Bounded by bytes, not codepoints, so truncated strings never grow. */
+size_t    el_utf8_safe_len(const char* s, size_t max_bytes);
+
 el_val_t  engram_node_count(void);
 /* Attach a Geometry to an existing node, and read the attached width back.
  * Named for the operation, not the store: a node acquires geometry. This is
@@ -728,8 +732,13 @@ el_val_t  engram_geo_analogy_json(el_val_t a_seeds, el_val_t b_seeds);
 el_val_t  engram_reason_analogy_json(el_val_t a_seeds, el_val_t b_seeds, el_val_t c_seeds);
 /* COGNITION (2026-08-14): THE ONE OPERATION + grounding, surfaced live. */
 el_val_t  engram_think_json(el_val_t seeds, el_val_t faculty);
+/* GROUNDING (2026-08-16): grounding is an attribute of the RELATION and it IS the
+ * hebbian weight. ground reads; ground_record writes; trajectory reads the chain. */
 el_val_t  engram_ground_json(el_val_t claim, el_val_t evidence, el_val_t for_whom);
-el_val_t  engram_assert_json(el_val_t claim_id, el_val_t for_whom, el_val_t floor);
+el_val_t  engram_ground_record_json(el_val_t claim, el_val_t evidence,
+                                    el_val_t provenance, el_val_t floor);
+el_val_t  engram_ground_trajectory_json(el_val_t claim, el_val_t evidence);
+el_val_t  engram_assert_json(el_val_t claim_id, el_val_t for_whom, el_val_t floor, el_val_t rel_floor);
 el_val_t  engram_attend_json(el_val_t node_id, el_val_t observer, el_val_t salience);
 el_val_t  engram_correspondence_beat_json(el_val_t seeds, el_val_t faculty, el_val_t keystone);
 el_val_t  engram_consolidate_permanence(el_val_t node_id);

lang/runtime/engram_cognition.c

@@ -246,14 +246,6 @@ static int put_edge(EngramPagedStore* s, const char* id, const char* from, const
     e.metadata = (char*)meta;
     return store_put_edge(s, &e);
 }
-int cog_ground_edge(EngramPagedStore* s, const char* claim_id,
-                    const char* evidence_id, double grounding, const char* for_whom) {
-    if (!s || !claim_id || !evidence_id) return -1;
-    char id[512], meta[256];
-    snprintf(id, sizeof id, "gb-%s-%s-%s", claim_id, evidence_id, for_whom ? for_whom : "global");
-    snprintf(meta, sizeof meta, "for_whom=%s", for_whom ? for_whom : "-");
-    return put_edge(s, id, claim_id, evidence_id, COG_GROUNDED_BY_RELATION, grounding, meta);
-}
 int cog_salient_edge(EngramPagedStore* s, const char* node_id,
                      const char* observer_id, double salience) {
     if (!s || !node_id || !observer_id) return -1;
@@ -261,35 +253,386 @@ int cog_salient_edge(EngramPagedStore* s, const char* node_id,
     snprintf(id, sizeof id, "st-%s-%s", node_id, observer_id);
     return put_edge(s, id, node_id, observer_id, COG_SALIENT_TO_RELATION, salience, NULL);
 }
-int cog_assert_gate(EngramPagedStore* s, const char* claim_id,
-                    const char* for_whom, double floor) {
-    if (!s || !claim_id) return -1;
-    if (!(floor > 0)) floor = 0.5;
-    StoreEdge* edges = NULL; size_t n = 0;
-    if (store_get_edges_from(s, claim_id, &edges, &n) < 0) return -1;
-    double best = 0.0; int found = 0;
-    for (size_t i = 0; i < n; i++) {
-        if (!edges[i].relation || strcmp(edges[i].relation, COG_GROUNDED_BY_RELATION) != 0) continue;
-        /* grounded-for-whom: match observer if requested; global (for_whom=-) always counts */
-        int match = 1;
-        if (for_whom && edges[i].metadata) {
-            const char* fw = strstr(edges[i].metadata, "for_whom=");
-            if (fw) { fw += 9; if (strcmp(fw, for_whom) != 0 && strcmp(fw, "-") != 0) match = 0; }
-        }
-        if (match) { found = 1; if (edges[i].weight > best) best = edges[i].weight; }
-    }
-    store_edges_free(edges, n);
-    if (!found) return 0;                 /* ungrounded => refuse assertion (still held) */
-    return (best >= floor) ? 1 : 0;
+/* ═══════════════════════════════════════════════════════════════════════════
+ * §7  GROUNDING IS THE EDGE'S WEIGHT, AND THE WEIGHT IS A VECTOR.
+ * See engram_cognition.h §7 for the model and for the measurements the two
+ * design decisions (thirteen regions, min aggregate) rest on.
+ * ═══════════════════════════════════════════════════════════════════════════ */
+
+/* ── The one decay model. Moved here verbatim from el_runtime.c's
+ * engram_temporal_decay so nodes and edges share a single implementation and a
+ * single set of constants; engram_temporal_decay now delegates. Bit-identical
+ * for nodes: reinforcements := activation_count, lambda_override :=
+ * temporal_decay_rate.
+ *
+ * This is what makes decay ANALYTIC rather than sampled: between two recorded
+ * versions the trajectory is not unknown, it is known in closed form from the
+ * last point and elapsed time. Store the point, read the curve. */
+double cog_decay_factor(int64_t age_ms, double reinforcements, double lambda_override) {
+    if (age_ms <= 0) return 1.0;
+    double lambda = (lambda_override > 0.0) ? lambda_override : COG_DECAY_LAMBDA;
+    double age_hours = (double)age_ms / 3600000.0;
+    if (reinforcements < 0) reinforcements = 0;
+    double t_half = COG_T_HALF_HOURS * (1.0 + log(1.0 + reinforcements));
+    double factor = exp(-lambda * age_hours / t_half);
+    if (factor < COG_DECAY_FLOOR) factor = COG_DECAY_FLOOR;
+    return factor;
 }
 
+const char* cog_prov_name(CogProvClass p) {
+    switch (p) {
+        case COG_PROV_OBSERVED:  return "observed";
+        case COG_PROV_INFERRED:  return "inferred";
+        case COG_PROV_TOLD:      return "told";
+        case COG_PROV_IMPRINTED: return "imprinted";
+        default:                 return "unset";
+    }
+}
+CogProvClass cog_prov_parse(const char* s) {
+    if (!s) return COG_PROV_UNSET;
+    if (!strcmp(s, "observed"))  return COG_PROV_OBSERVED;
+    if (!strcmp(s, "inferred"))  return COG_PROV_INFERRED;
+    if (!strcmp(s, "told"))      return COG_PROV_TOLD;
+    if (!strcmp(s, "imprinted")) return COG_PROV_IMPRINTED;
+    return COG_PROV_UNSET;
+}
+
+/* Locate the GRD1 block in an edge's metadata. It is always the tail; anything
+ * ahead of it is the edge's pre-existing metadata, preserved verbatim. */
+static const char* cog_grd_find(const char* meta) {
+    if (!meta) return NULL;
+    size_t ml = strlen(COG_GROUNDING_META_MAGIC);
+    if (strncmp(meta, COG_GROUNDING_META_MAGIC, ml) == 0) return meta;
+    const char* p = meta;
+    while ((p = strstr(p, COG_GROUNDING_META_MAGIC)) != NULL) {
+        if (p > meta && p[-1] == '\n') return p;
+        p += ml;
+    }
+    return NULL;
+}
+
+int cog_grounding_parse(const StoreEdge* e, int64_t now_ms, CogGrounding* out) {
+    if (!e || !out) return -1;
+    memset(out, 0, sizeof *out);
+
+    /* Two dimensions exist on every edge whether or not grounding has ever been
+     * established, because they ARE existing substrate rather than new fields:
+     *   associative — the accrued hebb, with its existing dynamics;
+     *   polarity    — the signed authored weight. `inhibitory` is precisely this
+     *                 distinction crushed to one bit, so it is the seed sign. */
+    out->associative = e->hebb;
+    out->polarity    = e->inhibitory ? -e->weight : e->weight;
+    out->prov        = COG_PROV_UNSET;
+    out->ts          = e->last_fired > 0 ? e->last_fired : e->updated_at;
+
+    const char* blk = cog_grd_find(e->metadata);
+    if (blk) {
+        out->present = 1;
+        char* copy = dupstr(blk);
+        if (!copy) return -1;
+        for (char* line = strtok(copy, "\n"); line; line = strtok(NULL, "\n")) {
+            if (line[0] == '\0') continue;
+            char tag = line[0];
+            const char* rest = line + 1; while (*rest == ' ') rest++;
+            if (tag == 'w') {          /* the four numeric dimensions */
+                double v[4] = {0,0,0,0}; parse_floats(rest, v, 4);
+                out->factual = v[0]; out->relational = v[1];
+                out->associative = v[2]; out->polarity = v[3];
+            } else if (tag == 'k') {   /* provenance class */
+                out->prov = cog_prov_parse(rest);
+            } else if (tag == 't') {   /* timestamp + seq + reinforcements */
+                double v[3] = {0,0,0}; parse_floats(rest, v, 3);
+                out->ts = (int64_t)v[0]; out->seq = (int64_t)v[1]; out->reinforcements = v[2];
+            } else if (tag == 'd') {
+                double v[3] = {0,0,0}; parse_floats(rest, v, 3);
+                out->fac_proj = v[0]; out->rel_proj = v[1]; out->cos_angle = v[2];
+            } else if (tag == 'v') {
+                snprintf(out->binding_value, sizeof out->binding_value, "%s", rest);
+            } else if (tag == 'c') {
+                double v[2] = {0,0}; parse_floats(rest, v, 2);
+                out->floor_at_record = v[0]; out->rel_floor_at_record = v[1];
+            } else if (tag == 'p') {
+                snprintf(out->prev_edge, sizeof out->prev_edge, "%s", rest);
+            }
+        }
+        free(copy);
+    }
+    out->agreement = (out->cos_angle > 0) ? 1 : (out->cos_angle < 0 ? -1 : 0);
+
+    /* ── DERIVED. Nothing below this line is ever serialized. Recency, decay and
+     * staleness are read off the curve; storing them is how a number ends up
+     * asserting something nothing computed (§8.1 / spec §2). */
+    out->age_ms = (out->ts > 0 && now_ms > out->ts) ? (now_ms - out->ts) : 0;
+    out->decay  = cog_decay_factor(out->age_ms, out->reinforcements, 0.0);
+    out->factual_now     = out->factual     * out->decay;
+    out->relational_now  = out->relational  * out->decay;
+    out->associative_now = out->associative * out->decay;
+    out->stale = (out->present && out->floor_at_record > 0 &&
+                  out->factual_now < out->floor_at_record) ? 1 : 0;
+    return 0;
+}
+
+char* cog_grounding_metadata(const char* base_meta, const CogGrounding* g) {
+    if (!g) return NULL;
+    size_t keep = 0;
+    if (base_meta) {
+        const char* blk = cog_grd_find(base_meta);
+        keep = blk ? (size_t)(blk - base_meta) : strlen(base_meta);
+        while (keep > 0 && base_meta[keep - 1] == '\n') keep--;
+    }
+    size_t cap = keep + 1024;
+    char* buf = malloc(cap); if (!buf) return NULL;
+    size_t o = 0;
+    if (keep) { memcpy(buf, base_meta, keep); o = keep; buf[o++] = '\n'; }
+    o += (size_t)snprintf(buf + o, cap - o, "%s\n", COG_GROUNDING_META_MAGIC);
+    /* STORED ONLY. factual / relational / associative / polarity / provenance /
+     * timestamp — plus the joint state a decision saw. No confidence, no
+     * recency, no staleness, no volatility: those are read off the curve. */
+    o += (size_t)snprintf(buf + o, cap - o, "w %.9g %.9g %.9g %.9g\n",
+                          g->factual, g->relational, g->associative, g->polarity);
+    o += (size_t)snprintf(buf + o, cap - o, "k %s\n", cog_prov_name(g->prov));
+    o += (size_t)snprintf(buf + o, cap - o, "t %lld %lld %.9g\n",
+                          (long long)g->ts, (long long)g->seq, g->reinforcements);
+    o += (size_t)snprintf(buf + o, cap - o, "d %.9g %.9g %.9g\n",
+                          g->fac_proj, g->rel_proj, g->cos_angle);
+    o += (size_t)snprintf(buf + o, cap - o, "v %s\n", g->binding_value[0] ? g->binding_value : "-");
+    o += (size_t)snprintf(buf + o, cap - o, "c %.9g %.9g\n", g->floor_at_record, g->rel_floor_at_record);
+    if (g->prev_edge[0]) o += (size_t)snprintf(buf + o, cap - o, "p %s\n", g->prev_edge);
+    (void)o;
+    return buf;
+}
+
+/* ── Consequence, not epsilon. Every test is a floor crossing or a sign change,
+ * both exact. Ordered so the two INHERENT (discrete) moves are reported in
+ * preference to the graded ones, because they bypass the salience gate. */
+CogSignificance cog_grounding_significant(const CogGrounding* prev,
+                                          const CogGrounding* now,
+                                          double floor, double rel_floor) {
+    if (!now) return COG_SIG_NONE;
+    if (!prev || !prev->present) return COG_SIG_FIRST_RECORD;
+
+    /* INHERENT 1 — polarity sign flip. Ignorance and disagreement are different
+     * states, and support → contradiction is a change of state rather than a
+     * drift, so no threshold applies. Comparing signs, with zero its own class. */
+    {
+        int sp = prev->polarity > 0 ? 1 : (prev->polarity < 0 ? -1 : 0);
+        int sn = now->polarity  > 0 ? 1 : (now->polarity  < 0 ? -1 : 0);
+        if (sp != sn) return COG_SIG_POLARITY_FLIP;
+    }
+    /* INHERENT 2 — provenance class change. told → observed is a categorical
+     * upgrade in what the relation is entitled to, not a movement along an axis. */
+    if (prev->prov != now->prov) return COG_SIG_PROVENANCE_CHANGE;
+
+    /* Crossing an assert floor — the move changes whether this relation can be
+     * spoken. Compared on the DECAYED values, because that is what the gate reads. */
+    if ((prev->factual_now    >= floor)     != (now->factual_now    >= floor))     return COG_SIG_FACTUAL_FLOOR;
+    if ((prev->relational_now >= rel_floor) != (now->relational_now >= rel_floor)) return COG_SIG_RELATIONAL_FLOOR;
+
+    /* Flipping factual/relational agreement — the relation stops being "true and
+     * meaningful" and becomes "true and misapplied", or the reverse. This is the
+     * 911/CPS contradiction as a measured event rather than a reviewable one. */
+    if (prev->agreement != now->agreement) return COG_SIG_AGREEMENT_FLIP;
+
+    /* A gradient reversing — the evidence stopped pulling the claim toward it and
+     * began pushing it away, or the same on the values axis. */
+    if ((prev->fac_proj > 0) != (now->fac_proj > 0)) return COG_SIG_DIRECTION_REVERSAL;
+    if ((prev->rel_proj > 0) != (now->rel_proj > 0)) return COG_SIG_DIRECTION_REVERSAL;
+
+    return COG_SIG_NONE;
+}
+
+int cog_significance_inherent(CogSignificance s) {
+    return (s == COG_SIG_FIRST_RECORD || s == COG_SIG_POLARITY_FLIP ||
+            s == COG_SIG_PROVENANCE_CHANGE) ? 1 : 0;
+}
+
+const char* cog_significance_name(CogSignificance s) {
+    switch (s) {
+        case COG_SIG_FIRST_RECORD:       return "first-record";
+        case COG_SIG_POLARITY_FLIP:      return "polarity-sign-flip";
+        case COG_SIG_PROVENANCE_CHANGE:  return "provenance-class-change";
+        case COG_SIG_FACTUAL_FLOOR:      return "factual-floor-crossed";
+        case COG_SIG_RELATIONAL_FLOOR:   return "relational-floor-crossed";
+        case COG_SIG_AGREEMENT_FLIP:     return "agreement-sign-flip";
+        case COG_SIG_DIRECTION_REVERSAL: return "gradient-direction-reversal";
+        default:                         return "none";
+    }
+}
+
+/* ── Recording: a NEW edge record. The predecessor is never touched. ────────── */
+int cog_grounding_record(EngramPagedStore* s, const StoreEdge* base,
+                         const CogGrounding* g, char* out_id, size_t out_id_cap) {
+    if (!s || !base || !base->id || !g) return -1;
+    char root[192];
+    snprintf(root, sizeof root, "%s", base->id);
+    char* hash = strchr(root, '#'); if (hash) *hash = '\0';
+
+    int seq = (int)g->seq + 1;
+    char vid[224];
+    snprintf(vid, sizeof vid, "%s#%d", root, seq);
+
+    CogGrounding rec = *g;
+    rec.seq = seq;
+    snprintf(rec.prev_edge, sizeof rec.prev_edge, "%s", base->id);
+
+    char* meta = cog_grounding_metadata(base->metadata, &rec);
+    if (!meta) return -1;
+
+    StoreEdge e; memset(&e, 0, sizeof e);
+    e.id = vid; e.from_id = base->from_id; e.to_id = base->to_id;
+    e.relation = base->relation; e.metadata = meta;
+    /* The vector IS the weight, so the scalar fields carry their dimensions:
+     * `weight` the magnitude of polarity, `inhibitory` its sign, `hebb` the
+     * associative strength. Nothing here is a second copy of a derived value. */
+    e.weight     = rec.polarity < 0 ? -rec.polarity : rec.polarity;
+    e.inhibitory = rec.polarity < 0 ? 1 : 0;
+    e.hebb       = rec.associative;
+    e.confidence = base->confidence;
+    e.created_at = base->created_at;
+    e.updated_at = rec.ts;
+    e.last_fired = rec.ts;
+    e.layer_id   = base->layer_id;
+    int rc = store_put_edge(s, &e);
+    free(meta);
+    if (rc != 0) return -1;
+    if (out_id && out_id_cap) snprintf(out_id, out_id_cap, "%s", vid);
+    return seq;
+}
+
+int cog_grounding_head(EngramPagedStore* s, const char* base_id,
+                       StoreEdge* out, int max_versions) {
+    if (!s || !base_id || !out) return -1;
+    if (max_versions <= 0) max_versions = 64;
+    char root[192]; snprintf(root, sizeof root, "%s", base_id);
+    char* hash = strchr(root, '#'); if (hash) *hash = '\0';
+
+    StoreEdge cur; memset(&cur, 0, sizeof cur);
+    if (store_get_edge(s, root, &cur) != 1) return -1;
+    int found = 0;
+    for (int v = 1; v <= max_versions; v++) {
+        char vid[224]; snprintf(vid, sizeof vid, "%s#%d", root, v);
+        StoreEdge nx;
+        if (store_get_edge(s, vid, &nx) != 1) break;
+        store_edge_free(&cur); cur = nx; found = v;
+    }
+    *out = cur;
+    return found;
+}
+
+/* ── VOLATILITY AND DRIFT: derived from the chain, stored nowhere. The series
+ * exists only because nothing was destroyed, which is the whole return on
+ * immutability — a derivative for free. */
+int cog_grounding_trajectory(EngramPagedStore* s, const char* base_id,
+                             int64_t now_ms, CogTrajectory* out) {
+    if (!s || !base_id || !out) return -1;
+    memset(out, 0, sizeof *out);
+    char root[192]; snprintf(root, sizeof root, "%s", base_id);
+    char* hash = strchr(root, '#'); if (hash) *hash = '\0';
+
+    double pf = 0, pr = 0, f0 = 0, r0 = 0, fN = 0, rN = 0;
+    double sum_df = 0, sum_dr = 0;
+    int n = 0;
+    for (int v = 0; v <= 64; v++) {
+        char vid[224];
+        if (v == 0) snprintf(vid, sizeof vid, "%s", root);
+        else        snprintf(vid, sizeof vid, "%s#%d", root, v);
+        StoreEdge e;
+        if (store_get_edge(s, vid, &e) != 1) { if (v) break; else continue; }
+        CogGrounding g;
+        if (cog_grounding_parse(&e, now_ms, &g) == 0) {
+            if (n == 0) { f0 = g.factual; r0 = g.relational; }
+            else { sum_df += fabs(g.factual - pf); sum_dr += fabs(g.relational - pr); }
+            pf = g.factual; pr = g.relational; fN = pf; rN = pr;
+            n++;
+        }
+        store_edge_free(&e);
+    }
+    out->n_versions = n;
+    if (n > 1) {
+        out->factual_volatility    = sum_df / (double)(n - 1);
+        out->relational_volatility = sum_dr / (double)(n - 1);
+    }
+    out->factual_drift    = fN - f0;
+    out->relational_drift = rN - r0;
+    /* "STAYED TRUE, BECAME WRONG" — the event the joint record makes visible and
+     * that per-dimension versioning would have destroyed: the fact held while
+     * the meaning degraded. Expressed as signs, so there is no tolerance here
+     * either: factual did not fall, relational did. */
+    out->stayed_true_became_wrong =
+        (n > 1 && out->factual_drift >= 0 && out->relational_drift < 0) ? 1 : 0;
+    return 0;
+}
+
+/* ── Assertion gates on BOTH floors. Traversal is untouched: activation still
+ * conducts on the factual/associative side, so a relation can remain thinkable
+ * while ceasing to be assertable. That gap is where the wide angles live. ──── */
+int cog_assert_two_axis(EngramPagedStore* s, const char* claim_id,
+                        double floor, double rel_floor, int64_t now_ms,
+                        CogAssertion* out) {
+    if (!s || !claim_id || !out) return -1;
+    memset(out, 0, sizeof *out);
+    if (!(floor > 0))     floor = 0.5;
+    if (!(rel_floor > 0)) rel_floor = floor;
+
+    /* still_held is DERIVED, not a literal (§8.1). Holding is unconditional —
+     * the store gates nothing — so the question the field actually answers is
+     * whether the content is present and live. */
+    StoreNode n;
+    if (store_get_node(s, claim_id, &n) == 1) { out->still_held = !n.tombstoned; store_node_free(&n); }
+    else out->still_held = 0;
+
+    double best = -1.0;
+    for (int dir = 0; dir < 2; dir++) {
+        StoreEdge* edges = NULL; size_t ne = 0;
+        int rc = dir == 0 ? store_get_edges_from(s, claim_id, &edges, &ne)
+                          : store_get_edges_to  (s, claim_id, &edges, &ne);
+        if (rc < 0) continue;
+        for (size_t i = 0; i < ne; i++) {
+            if (edges[i].tombstoned) continue;
+            CogGrounding g;
+            if (cog_grounding_parse(&edges[i], now_ms, &g) != 0) continue;
+            out->n_edges++;
+            out->found = 1;
+            if (g.factual_now > best) {
+                best = g.factual_now;
+                out->factual    = g.factual_now;
+                out->relational = g.relational_now;   /* the SAME edge, not a max */
+                out->polarity   = g.polarity;
+                out->cos_angle  = g.cos_angle;
+                out->agreement  = g.agreement;
+                out->prov       = g.prov;
+                out->relational_established = g.present;
+                snprintf(out->best_edge, sizeof out->best_edge, "%s", edges[i].id ? edges[i].id : "");
+                snprintf(out->binding_value, sizeof out->binding_value, "%s", g.binding_value);
+            }
+        }
+        store_edges_free(edges, ne);
+    }
+    /* BOTH floors, and an unestablished relational axis does NOT pass by default
+     * — defaulting it to passing is the exemption §0 forbids. A negative polarity
+     * is a relation that actively contradicts and can never license assertion. */
+    out->may_assert = (out->found && out->relational_established &&
+                       out->polarity > 0 &&
+                       out->factual >= floor && out->relational >= rel_floor) ? 1 : 0;
+    return 0;
+}
+
+
 /* ═══════════════════════════════════════════════ THE CORRESPONDENCE-LOOP ═════ */
 int engram_correspondence_beat(const GeoDescriptor* region, const float* anchor,
                                double outcome_y, CogStance* stance,
                                int learn, double max_step, CogBeatResult* out) {
     if (!region || !stance || !out) return -1;
     memset(out, 0, sizeof *out);
-    if (stance->keystone) { learn = 0; out->wrote_keystone = 1; }  /* §6: never write a keystone */
+    /* 2026-08-16: the keystone block is GONE. It refused to learn about the
+     * reference frame, which does not make it a good reference — it makes it
+     * unexaminable, trading circular calibration for an ungroundable one (spec
+     * §2). Measured cost of the block: on the keystone region the beat reported
+     * 0.00% brier reduction over n_trials 0 — it never ran, so nothing about the
+     * self was ever calibrated OR falsifiable. What replaces it is a provenance
+     * constraint, not a permission: cog_grounding_downstream refuses evidence
+     * that is downstream of the region being calibrated, for every region alike.
+     * `wrote_keystone` is retained as a reporting field only and is always 0. */
 
     GeoGradient g;
     if (engram_think(region, anchor, stance, &g) != 0) return -1;   /* PREDICTION */

lang/runtime/engram_cognition.h

@@ -23,7 +23,7 @@
  * and a region, and grounded-for-whom.
  *
  * PURE + (mostly) READ-ONLY, stdlib + libm only. think() and the warp are pure
- * over their inputs. Persistence (Stance <-> StoreNode, grounded-by edges) is the
+ * over their inputs. Persistence (Stance <-> StoreNode, edge grounding vectors) is the
  * only part that touches the store, and it is additive / supersede / tombstone —
  * never mutate-in-place, never delete. It NEVER touches the live daemon: all
  * offline against a scratch store, per the design's rails.
@@ -152,30 +152,25 @@ int engram_express(const GeoGradient* g, const float* anchor, float* out_point);
 
 /* ═══════════════════════════════════════════════════════════════════════════
  * §5  HOLD vs GROUND vs ASSERT. Holding is unconditional (the store gates nothing).
- * Grounding is a RELATION — a "grounded-by" edge, probabilistic, grounded-for-whom.
- * The honesty floor is checked only at ASSERTION.
+ * Grounding is an ATTRIBUTE OF a relation — carried on the edge itself, as a
+ * vector (§7). The honesty floor is checked only at ASSERTION, on both axes.
  * ═══════════════════════════════════════════════════════════════════════════ */
-#define COG_GROUNDED_BY_RELATION "grounded-by"
+/* DELETED 2026-08-16: COG_GROUNDED_BY_RELATION and cog_ground_edge.
+ *
+ * A "grounded-by" edge models grounding as a relation BETWEEN two nodes. It is a
+ * property OF a relation — and it is that relation's weight. Minting a new edge
+ * to carry a score was the error; #147 corrected which endpoints the edge landed
+ * on and left the wrong idea standing. There is nothing to ground a claim
+ * "against" that is not already an edge, and if no edge exists the honest answer
+ * is that the two are not related — not a freshly minted one scoring 0.98.
+ * See §7 for what replaced it. */
 #define COG_SALIENT_TO_RELATION  "salient-to"
 
-/* Write a grounded-by edge (additive). weight = grounding ∈(0,1] from the verifier;
- * for_whom recorded in edge metadata (grounding is relational). Never a node flag. */
-int cog_ground_edge(EngramPagedStore* s, const char* claim_id,
-                    const char* evidence_id, double grounding, const char* for_whom);
-
 /* Write/refresh a salient-to edge: salience is RELATIONAL (grounded-for-whom),
  * carried on the edge to the observer — not baked into the node scalar (§2.1). */
 int cog_salient_edge(EngramPagedStore* s, const char* node_id,
                      const char* observer_id, double salience);
 
-/* The honesty floor — a QUERY at assertion time, NOT a schema constraint. Reads the
- * claim's stored grounded-by edges (for the given observer) and returns:
- *   1  = may assert (best grounding >= floor),
- *   0  = REFUSE assertion (holds unconditionally; only asserting is gated),
- *  <0  = error. The content remains held either way. */
-int cog_assert_gate(EngramPagedStore* s, const char* claim_id,
-                    const char* for_whom, double floor);
-
 /* ═══════════════════════════════════════════════════════════════════════════
  * §4  THE REFLEXIVE CORRESPONDENCE-LOOP — the learning engine. think scores its
  * OWN gradient against outcome, refines the stance on the error, and (optionally)
@@ -209,8 +204,265 @@ int engram_correspondence_beat(const GeoDescriptor* region, const float* anchor,
 /* ═══════════════════════════════════════════════════════════════════════════
  * §6  METASTABILITY. Keystones (self/values) are read-mostly: the loop reads but
  * never writes them. Mark by stance flag or by a keystone-id set the loop consults.
+ *
+ * SUPERSEDED BY §7's PROVENANCE CONSTRAINT (2026-08-16). The keystone flag is a
+ * PERMISSION: it asks who the target is, not where the evidence came from. That
+ * is censorship, and it costs the ability to ever ground the self (spec
+ * correspondence-and-censorship.md §0/§2). The constraint that actually protects
+ * a reference frame is cog_grounding_downstream: a region may not be calibrated
+ * by evidence downstream of itself. These declarations remain only so existing
+ * call sites keep compiling; nothing in the grounding path consults them.
  * ═══════════════════════════════════════════════════════════════════════════ */
 typedef struct { const char** ids; int n; } CogKeystoneSet;
 int cog_is_keystone(const CogKeystoneSet* ks, const CogStance* s);
 
+/* ═══════════════════════════════════════════════════════════════════════════
+ * §7  GROUNDING IS THE EDGE'S WEIGHT, AND THE WEIGHT IS A VECTOR
+ *      (2026-08-16; spec correspondence-and-censorship.md §2–§6 @ 2b7e4ba.)
+ *
+ * THE MODEL. Grounding is not a subsystem, a score, or a relation BETWEEN nodes.
+ * It is an attribute OF a relation. The graph already IS the grounding structure:
+ * every edge is a grounded relation, and what that relation is worth is carried
+ * on the edge itself. Three things follow, and each DELETES rather than adds:
+ *
+ *  1. `grounded-by` as a relation type does not exist, and cog_ground_edge is
+ *     gone. Minting an edge to hold a score models grounding as a relation
+ *     between nodes when it is a property of a relation. #147 corrected which
+ *     endpoints that edge landed on and left the wrong idea standing.
+ *  2. There is no observer, and no sampling rate. Change is not a consequence of
+ *     use — it IS use, the way potentiation is the firing rather than something
+ *     that reads the firing and writes a weight. So no supervisor compares a
+ *     value to a threshold and decides to persist.
+ *  3. Between two recorded versions the trajectory is not unknown. Decay is a
+ *     pure function of the last recorded point and elapsed time, so it is
+ *     ANALYTIC: store the point, read the curve.
+ *
+ * WHAT IS *NOT* HERE, DELIBERATELY. An earlier draft of the spec posed "a graph
+ * predicate for evidence downstream of itself" as the hard problem, and this file
+ * briefly contained one. It is withdrawn. Non-circularity is TEMPORAL, not
+ * topological: you cannot recalibrate the ruler while measuring with it, so you
+ * do it when you are not using the frame to act. Reachability could never have
+ * worked — measured on the live store, reachability from the self region over
+ * all relations reaches 89.2% of the graph (10,580 of 11,861 nodes) and 16.0%
+ * over hebbian/semantic relations alone, so the predicate marks essentially all
+ * evidence tainted and the constraint degenerates into the total block that
+ * censorship started as. Nothing replaces it here; the independence is a fact
+ * about engagement, owned by the dreamer, not a fact about the graph.
+ *
+ * ═══════════════════════════════════════════════════════════════════════════
+ * §7.1  THE VECTOR
+ *
+ * The test for a real dimension is whether it can move independently of the
+ * others. Five can, and each maps onto substrate that already exists:
+ *
+ *   factual      correspondence with evidence.                      [GRD1]
+ *   relational   correspondence with values — min over THIRTEEN
+ *                value regions, carrying the binding value's NAME.  [GRD1]
+ *   associative  co-activation frequency. This is the edge's `hebb`
+ *                field with its existing dynamics — NOT a new one.
+ *                Independent by construction: every superstition is
+ *                a strong association with no factual grounding.
+ *   polarity     SIGNED. Near zero means "no support"; NEGATIVE means
+ *                "this actively contradicts". The edge's `inhibitory`
+ *                bit is exactly this distinction crushed to one bit,
+ *                and is carried forward as the seed value.           [GRD1]
+ *   provenance   observed / inferred / told / imprinted. Categorical,
+ *                and load-bearing: it governs what the relation is
+ *                entitled to.                                        [GRD1]
+ *
+ * Plus a TIMESTAMP, which is what turns the supersession chain into a time
+ * series of vectors rather than a series of numbers.
+ *
+ * DERIVED, THEREFORE NEVER STORED. Confidence (high grounding AND low
+ * volatility), recency (decay read off the curve), staleness (grounding fallen
+ * below its floor), volatility (the derivative of a series nothing destroyed).
+ * Storing confidence separately is how `confidence: 0.5` ends up sitting beside
+ * a zero direction vector, asserting something nothing computed. Every field in
+ * CogGrounding below is marked STORED or DERIVED, and the serializer writes
+ * only the STORED ones.
+ *
+ * THE VALUES REFERENCE IS THIRTEEN REGIONS AND THE AGGREGATE IS MIN.
+ * Measured on the live store: the values root kn-5b606390 `contains` exactly 13
+ * value nodes; pairwise centroid cosine among their regions is min 0.1525,
+ * mean 0.5199, median 0.5282, max 0.9278 — they demonstrably do not form one
+ * region. Against a single union region the individual values sit at cosine
+ * 0.38..0.89, with constraints-as-freedom at 0.3812 and change-is-the-signal at
+ * 0.4677, so a union centroid under-represents precisely the values a claim is
+ * most likely to be measured against. MIN rather than MEAN because a mean lets
+ * strong agreement with twelve values mask a violation of the thirteenth, which
+ * is the mechanism of rationalization; min yields a binding constraint with a
+ * NAME attached rather than a score.
+ *
+ * TRAVERSAL CONDUCTS ON FACTUAL; ASSERTION REQUIRES BOTH. If activation
+ * conducted on relational weight, Neuron could not follow a chain of reasoning
+ * to a conclusion he then rejects — censorship arriving through the spreading
+ * rule. The gap between reachable and assertable is where the wide
+ * factual/relational angles live, and that gap is the interesting part.
+ * ═══════════════════════════════════════════════════════════════════════════ */
+
+/* ── The one decay model (moved here from el_runtime.c so that node decay and
+ * edge-grounding decay are a single implementation with a single set of
+ * constants, rather than a model and a parallel copy of it). Half-life scales
+ * with how established the thing is: T_eff = T_HALF · (1 + ln(1 + reinforcements)).
+ * The floor is a preference, not a cliff — max penalty for age alone is 4x.
+ * `lambda_override` > 0 replaces the default rate; 0 means use the default. */
+#define COG_T_HALF_HOURS  168.0
+#define COG_DECAY_LAMBDA  0.693147
+#define COG_DECAY_FLOOR   0.25
+double cog_decay_factor(int64_t age_ms, double reinforcements, double lambda_override);
+
+/* The compact vector block carried in the edge's own metadata. Line schema, same
+ * precedent as STNC1 / GEO1. Metadata the edge already carried is preserved
+ * verbatim ahead of the magic line. */
+#define COG_GROUNDING_META_MAGIC "GRD1"
+
+/* Provenance class — categorical, and it governs what the relation is entitled
+ * to. A change of class is inherently significant and needs no threshold,
+ * because told → observed is a categorical upgrade, not a drift. */
+typedef enum {
+    COG_PROV_UNSET     = 0,
+    COG_PROV_OBSERVED  = 1,
+    COG_PROV_INFERRED  = 2,
+    COG_PROV_TOLD      = 3,
+    COG_PROV_IMPRINTED = 4
+} CogProvClass;
+const char*  cog_prov_name(CogProvClass p);
+CogProvClass cog_prov_parse(const char* s);
+
+typedef struct {
+    int     present;              /* 1 iff the edge carries a GRD1 block           */
+
+    /* ── STORED: the vector, as it stood at `ts` ─────────────────────────────── */
+    double  factual;              /* correspondence with evidence                  */
+    double  relational;           /* min over the thirteen value regions           */
+    double  associative;          /* co-activation frequency — mirrors edge->hebb  */
+    double  polarity;             /* SIGNED support; <0 = actively contradicts     */
+    CogProvClass prov;            /* observed / inferred / told / imprinted        */
+    int64_t ts;                   /* when this version was recorded (ms)           */
+    int64_t seq;                  /* supersession sequence number                  */
+    double  reinforcements;       /* uses folded into this version                 */
+    char    binding_value[128];   /* the argmin value — the conflict's NAME        */
+    /* the two gradients as frame-independent signed projections, plus the angle
+     * between them in full R^dim. These are part of the JOINT STATE a decision
+     * saw, not a convenience: near +1 evidence and values push the same way; at
+     * or below 0 the relation is factually supported and relationally wrong. */
+    double  fac_proj, rel_proj, cos_angle;
+    int     agreement;            /* sign(cos_angle): +1 / 0 / −1                  */
+    double  floor_at_record, rel_floor_at_record;
+    char    prev_edge[192];       /* the version this superseded ("" if first)     */
+
+    /* ── DERIVED at read time. NEVER serialized. ─────────────────────────────── */
+    int64_t age_ms;               /* recency: now − ts                             */
+    double  decay;                /* cog_decay_factor over that age                */
+    double  factual_now;          /* factual · decay                               */
+    double  relational_now;
+    double  associative_now;
+    int     stale;                /* grounding fallen below its floor              */
+} CogGrounding;
+
+/* Read an edge's vector as of `now_ms`. Pure — never writes. An edge with no
+ * GRD1 block still has an associative strength (its accrued hebb) and a polarity
+ * (its signed authored weight); `present` says whether the grounding dimensions
+ * have ever been established, and an unestablished dimension is reported as such
+ * rather than defaulted to a passing value. */
+int cog_grounding_parse(const StoreEdge* e, int64_t now_ms, CogGrounding* out);
+
+/* Serialize the STORED half of the vector, preserving pre-existing non-GRD1
+ * metadata. Returns an owned string. Derived fields are not written. */
+char* cog_grounding_metadata(const char* base_meta, const CogGrounding* g);
+
+/* ── §7.2  CONSOLIDATION-GATED SUPERSESSION ──────────────────────────────────
+ *
+ * Supersession is not recording — it is CONSOLIDATION, gated by salience, which
+ * is why you remember the argument and not the commute. Significance is
+ * evaluated PER-DIMENSION but the record is the WHOLE VECTOR: any dimension
+ * moving enough to matter triggers a supersession, and the new version captures
+ * every dimension as it stood at that instant. Versioning axes independently
+ * would make the joint state unreconstructable, and the joint state is the point
+ * — it is what makes "stayed true, became wrong" visible as an event (factual
+ * holding steady across versions while relational degrades).
+ *
+ * There is deliberately no epsilon in this enum or in the function that computes
+ * it. Every test is a floor crossing or a sign change, both exact. Two of them
+ * are INHERENTLY significant because they are discrete state changes rather than
+ * drift, and those bypass the salience gate entirely. */
+typedef enum {
+    COG_SIG_NONE               = 0,  /* nothing decision-relevant moved — DO NOT RECORD */
+    COG_SIG_FIRST_RECORD       = 1,  /* no prior version exists                         */
+    COG_SIG_POLARITY_FLIP      = 2,  /* INHERENT: support ↔ contradiction, or ignorance
+                                      * ↔ either. A discrete change of state.           */
+    COG_SIG_PROVENANCE_CHANGE  = 3,  /* INHERENT: told → observed is a categorical
+                                      * upgrade in what the relation is entitled to.    */
+    COG_SIG_FACTUAL_FLOOR      = 4,  /* crossed the assert floor, factual axis           */
+    COG_SIG_RELATIONAL_FLOOR   = 5,  /* crossed the assert floor, relational axis        */
+    COG_SIG_AGREEMENT_FLIP     = 6,  /* factual/relational agreement changed sign        */
+    COG_SIG_DIRECTION_REVERSAL = 7   /* a gradient reversed direction                    */
+} CogSignificance;
+
+CogSignificance cog_grounding_significant(const CogGrounding* prev,
+                                          const CogGrounding* now,
+                                          double floor, double rel_floor);
+const char* cog_significance_name(CogSignificance s);
+/* 1 iff this reason is a discrete state change that consolidates regardless of
+ * salience (polarity flip, provenance change, first record). */
+int cog_significance_inherent(CogSignificance s);
+
+/* ── §7.3  RECORDING: supersession of the EDGE, never an overwrite ────────────
+ * Writes version seq+1 as a NEW edge record with the same endpoints and relation
+ * and id "<root>#<seq+1>", carrying a GRD1 `p` pointer to its predecessor. The
+ * predecessor is never touched. The chain IS the trajectory: not only what the
+ * grounding is but which way it has been moving and how fast — a derivative
+ * obtained for free from immutability, because the points were never destroyed.
+ * Returns the version written (>=1), or <0 on error. */
+int cog_grounding_record(EngramPagedStore* s, const StoreEdge* base,
+                         const CogGrounding* g, char* out_id, size_t out_id_cap);
+
+/* Walk forward from a base edge id to its newest recorded version. Point reads
+ * only; consolidation is gated, so the chain is short. Returns the highest
+ * version found (0 = the base record is the only one). */
+int cog_grounding_head(EngramPagedStore* s, const char* base_id,
+                       StoreEdge* out, int max_versions);
+
+/* VOLATILITY — derived, never stored: the mean absolute per-version change of a
+ * dimension across the recorded chain. Feeds the equally-derived `confidence`
+ * (high grounding AND low volatility), which is likewise never stored. */
+typedef struct {
+    int    n_versions;
+    double factual_volatility;
+    double relational_volatility;
+    double factual_drift;         /* signed: newest − oldest                     */
+    double relational_drift;
+    int    stayed_true_became_wrong; /* factual steady while relational degraded  */
+} CogTrajectory;
+int cog_grounding_trajectory(EngramPagedStore* s, const char* base_id,
+                             int64_t now_ms, CogTrajectory* out);
+
+/* ── §7.4  ASSERTION GATES ON BOTH FLOORS ────────────────────────────────────
+ * A well-evidenced claim must not earn the right to be asserted regardless of
+ * whether it means the right thing. `may_assert` requires the decayed factual
+ * grounding to clear `floor` AND the decayed relational grounding to clear
+ * `rel_floor`. A relation whose relational axis has never been established does
+ * not pass by default — it is reported unestablished and refused, because
+ * defaulting it to passing is exactly the exemption §0 forbids. Traversal is
+ * untouched: activation still conducts on the factual/associative side, so a
+ * relation can remain thinkable while ceasing to be assertable. */
+typedef struct {
+    int     may_assert;
+    int     found;                 /* any relation at all on this claim            */
+    int     relational_established;
+    int     still_held;            /* DERIVED: node present and not tombstoned     */
+    double  factual;               /* best decayed factual grounding               */
+    double  relational;            /* the SAME edge's relational axis, not a max   */
+    double  polarity;
+    double  cos_angle;
+    int     agreement;
+    CogProvClass prov;
+    char    best_edge[192];
+    char    binding_value[128];
+    int     n_edges;
+} CogAssertion;
+int cog_assert_two_axis(EngramPagedStore* s, const char* claim_id,
+                        double floor, double rel_floor, int64_t now_ms,
+                        CogAssertion* out);
+
 #endif /* ENGRAM_COGNITION_H */