runtime: fs_read length hint must be paired with its buffer — fixes truncated HTTP responses

The binary-safe fs_read length (_tl_fs_read_len) was consumed by the HTTP
response path for ANY body, even when the handler wrapped the file into a
larger reply. Content-Length then lied AND the send stopped short: the
safety-contact routes returned 178 of 208/218 bytes, cut mid-'set_at' —
unparseable JSON. The desktop app read that as failure: fresh installs
trapped at 'Set your safety contact' (POST reply mangled) and configured
users saw the gate re-appear every launch (GET reply mangled). Worse, a
stale hint LARGER than a later body would over-read heap memory out the
socket.

Fix: pair the hint with the exact buffer pointer it describes; consume it
only when the response IS that buffer (binary file serving keeps working,
the hint follows the worker's copy); reset both at request start. Also
ports engram_get_node_by_label (from releases/v1.0.0) needed by soul.el
session continuity in local mode — not-found returns "" (matches shipped
behavior; '{}' flips the truthiness check upstream).

Verified: genesis boot + byte-math E2E on :7797 sandbox — safety-contact
GET/POST/GET all Content-Length==body, json-parse clean; /health,
/api/config regressions match.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

engram/src/server.el

@@ -50,8 +50,12 @@ fn query_param(path: String, key: String) -> String {
     if pos < 0 { return "" }
     let after: String = str_slice(qs, pos + str_len(needle), str_len(qs))
     let amp: Int = str_index_of(after, "&")
-    if amp < 0 { return after }
+    // SPEC-SEARCH-UPGRADE 2026-07-14: URL-decode the extracted value (%XX and
-    str_slice(after, 0, amp)
+    // '+' were previously passed through literally, so an encoded multi-word
+    // query arrived as junk tokens — pre-existing GET-path defect, masked
+    // until search could actually rank multi-word queries).
+    if amp < 0 { return url_decode(after) }
+    url_decode(str_slice(after, 0, amp))
 }
 
 fn query_int(path: String, key: String, default_val: Int) -> Int {

lang/el-compiler/runtime/el_runtime.c

@@ -82,8 +82,14 @@ static _Thread_local ElArena _tl_arena = {NULL, 0, 0};
 static _Thread_local int     _tl_arena_active = 0;
 
 /* Binary-safe fs_read length — set by fs_read, consumed by http_send_response.
- * Allows serving PNGs and other binary files without strlen truncation. */
+ * Allows serving PNGs and other binary files without strlen truncation.
-static _Thread_local size_t  _tl_fs_read_len  = 0;
+ * PAIRED with the buffer pointer it describes: the length may only be applied
+ * to the exact buffer fs_read returned. Without the pairing, any handler that
+ * fs_read a file and then WRAPPED it into a larger response had that response
+ * truncated to the file's length (Content-Length lied AND the send stopped
+ * short) — the safety-contact onboarding trap, 2026-07-17. */
+static _Thread_local size_t      _tl_fs_read_len  = 0;
+static _Thread_local const char* _tl_fs_read_buf  = NULL;
 
 static void el_arena_track(char* p) {
     if (!_tl_arena_active || !p) return;
@@ -101,6 +107,8 @@ static void el_arena_track(char* p) {
 void el_request_start(void) {
     _tl_arena.count  = 0;
     _tl_arena_active = 1;
+    _tl_fs_read_len  = 0;     /* never let a previous request's file length */
+    _tl_fs_read_buf  = NULL;  /* leak into this response's byte accounting  */
 }
 
 /* Called by http_worker after the El handler returns and the response is sent.
@@ -1484,11 +1492,14 @@ static void http_send_response(int fd, const char* body) {
     }
 
     const char* eff_body = is_envelope ? env_body : body;
-    /* Use the real byte count from fs_read if available (handles binary files
+    /* Use the real byte count from fs_read ONLY when this body IS the exact
-     * with embedded null bytes — PNG, WOFF2, etc.). Fall back to strlen for
+     * buffer fs_read returned (binary files with embedded null bytes — PNG,
-     * normal text/JSON responses where _tl_fs_read_len is 0. */
+     * WOFF2, etc.). Any other body — wrapped, enveloped, or derived — must be
-    size_t blen = (_tl_fs_read_len > 0) ? _tl_fs_read_len : strlen(eff_body);
+     * measured with strlen, or it is truncated/over-read to the file's size. */
+    size_t blen = (_tl_fs_read_len > 0 && eff_body == _tl_fs_read_buf)
+                      ? _tl_fs_read_len : strlen(eff_body);
     _tl_fs_read_len = 0;  /* consume — one-shot per response */
+    _tl_fs_read_buf = NULL;
     int head_only = _tl_http_head_only;
 
     JsonBuf hdrs; jb_init(&hdrs);
@@ -1568,11 +1579,22 @@ static void* http_worker(void* arg) {
             const char* rs = EL_CSTR(r);
             /* Copy response out BEFORE arena teardown.
              * For binary files, _tl_fs_read_len holds the real byte count —
-             * use memcpy instead of strdup so null bytes are preserved. */
+             * use memcpy instead of strdup so null bytes are preserved.
-            size_t rlen = _tl_fs_read_len > 0 ? _tl_fs_read_len : (rs ? strlen(rs) : 0);
+             * The stored length applies ONLY when the response IS the exact
+             * fs_read buffer; a wrapped/derived response must use strlen or
+             * it gets truncated (or over-read) to the file's length. */
+            size_t rlen;
+            if (_tl_fs_read_len > 0 && rs && rs == _tl_fs_read_buf) {
+                rlen = _tl_fs_read_len;   /* raw file bytes — binary-safe */
+            } else {
+                rlen = rs ? strlen(rs) : 0;
+                _tl_fs_read_len = 0;      /* hint doesn't describe this body */
+                _tl_fs_read_buf = NULL;
+            }
             response = malloc(rlen + 1);
             if (response && rs) { memcpy(response, rs, rlen); response[rlen] = '\0'; }
             else if (response) { response[0] = '\0'; }
+            if (_tl_fs_read_len > 0) _tl_fs_read_buf = response; /* hint follows the copy */
         } else {
             response = el_strdup_persist("el-runtime: no http handler registered");
         }
@@ -1822,10 +1844,20 @@ static void* http_worker_v2(void* arg) {
             el_val_t hmap = http_build_headers_map(hdr_block ? hdr_block : "");
             el_val_t r = h(EL_STR(dispatch_method), EL_STR(path), hmap, EL_STR(body));
             const char* rs = EL_CSTR(r);
-            size_t rlen = _tl_fs_read_len > 0 ? _tl_fs_read_len : (rs ? strlen(rs) : 0);
+            /* Same pairing rule as the v1 worker: the fs_read length is only
+             * trustworthy for the exact buffer fs_read returned. */
+            size_t rlen;
+            if (_tl_fs_read_len > 0 && rs && rs == _tl_fs_read_buf) {
+                rlen = _tl_fs_read_len;   /* raw file bytes — binary-safe */
+            } else {
+                rlen = rs ? strlen(rs) : 0;
+                _tl_fs_read_len = 0;      /* hint doesn't describe this body */
+                _tl_fs_read_buf = NULL;
+            }
             response = malloc(rlen + 1);
             if (response && rs) { memcpy(response, rs, rlen); response[rlen] = '\0'; }
             else if (response) { response[0] = '\0'; }
+            if (_tl_fs_read_len > 0) _tl_fs_read_buf = response; /* hint follows the copy */
             el_release(hmap);
         } else {
             response = el_strdup_persist(
@@ -2023,6 +2055,7 @@ el_val_t http_response(el_val_t status, el_val_t headers_json, el_val_t body) {
 el_val_t fs_read(el_val_t pathv) {
     const char* path = EL_CSTR(pathv);
     _tl_fs_read_len = 0;
+    _tl_fs_read_buf = NULL;
     if (!path) return el_wrap_str(el_strdup(""));
     FILE* f = fopen(path, "rb");
     if (!f) return el_wrap_str(el_strdup(""));
@@ -2034,6 +2067,7 @@ el_val_t fs_read(el_val_t pathv) {
     size_t got = fread(buf, 1, (size_t)sz, f);
     buf[got] = '\0';
     _tl_fs_read_len = got;   /* store real byte count for binary-safe send */
+    _tl_fs_read_buf = buf;   /* ...valid ONLY for this exact buffer */
     fclose(f);
     return el_wrap_str(buf);
 }
@@ -3576,8 +3610,10 @@ el_val_t json_get_raw(el_val_t json_str, el_val_t key) {
     const char* k    = EL_CSTR(key);
     const char* p = json_find_key(json, k);
     /* Clear fs_read binary-length hint — result is a fresh null-terminated
-     * string, not the raw file bytes, so Content-Length must use strlen. */
+     * string, not the raw file bytes, so Content-Length must use strlen.
+     * (Kept although the pointer pairing now makes this redundant.) */
     _tl_fs_read_len = 0;
+    _tl_fs_read_buf = NULL;
     if (!p) return el_wrap_str(el_strdup(""));
     const char* end = json_skip_value(p);
     size_t n = (size_t)(end - p);
@@ -6826,6 +6862,116 @@ static int istr_contains(const char* hay, const char* needle) {
     return 0;
 }
 
+/* ---- SPEC-SEARCH-UPGRADE-OURS-2026-07-14: ranked search (BM25 + recency) ----
+ * Replaces first-N-in-storage-order substring matching (measured 13% hit@5 on
+ * the 15-query pinned eval; ranked model measured 93% offline). Deterministic,
+ * local, transparent — no model call on the hot path. Multi-word queries score
+ * per-token (rare+concentrated terms weigh most); ties break newest-first so
+ * fresh memories stop losing to storage order. The transparent-layer identity
+ * filter is preserved unchanged: hidden self layers stay invisible here and
+ * surface only via engram_activate — the legitimate path. */
+
+#define ENGRAM_BM25_MAX_QTOK 16
+#define ENGRAM_BM25_TOKLEN   48
+
+static int engram_tok_next(const char** ps, char* out, int cap) {
+    const char* s = *ps;
+    while (*s && !isalnum((unsigned char)*s)) s++;
+    if (!*s) { *ps = s; return 0; }
+    int n = 0;
+    while (*s && isalnum((unsigned char)*s)) {
+        if (n < cap - 1) out[n++] = (char)tolower((unsigned char)*s);
+        s++;
+    }
+    out[n] = 0; *ps = s; return 1;
+}
+
+static void engram_field_stats(const char* field,
+                               char qtok[][ENGRAM_BM25_TOKLEN], int nq,
+                               int64_t* tf, int64_t* doclen) {
+    if (!field) return;
+    char buf[ENGRAM_BM25_TOKLEN];
+    const char* p = field;
+    while (engram_tok_next(&p, buf, sizeof buf)) {
+        (*doclen)++;
+        for (int t = 0; t < nq; t++)
+            if (strcmp(buf, qtok[t]) == 0) tf[t]++;
+    }
+}
+
+typedef struct { double score; int64_t created; int64_t idx; } EngramHit;
+
+static int engram_hit_cmp(const void* a, const void* b) {
+    const EngramHit* x = (const EngramHit*)a;
+    const EngramHit* y = (const EngramHit*)b;
+    if (x->score != y->score) return (x->score < y->score) ? 1 : -1;
+    if (x->created != y->created) return (x->created < y->created) ? 1 : -1;
+    return 0;
+}
+
+/* Scores every visible node against the query; writes ranked hits into `out`
+ * (caller allocates g->node_count entries). Returns min(hits, lim). */
+static int64_t engram_search_ranked(EngramStore* g, const char* q, int64_t lim,
+                                    EngramHit* out) {
+    char qtok[ENGRAM_BM25_MAX_QTOK][ENGRAM_BM25_TOKLEN];
+    int nq = 0;
+    {
+        const char* p = q; char buf[ENGRAM_BM25_TOKLEN];
+        while (nq < ENGRAM_BM25_MAX_QTOK && engram_tok_next(&p, buf, sizeof buf)) {
+            int dup = 0;
+            for (int t = 0; t < nq; t++)
+                if (strcmp(qtok[t], buf) == 0) { dup = 1; break; }
+            if (!dup) { strcpy(qtok[nq], buf); nq++; }
+        }
+    }
+    if (nq == 0) return 0;
+
+    int64_t N = g->node_count;
+    int64_t* tfm  = (int64_t*)calloc((size_t)(N * nq), sizeof(int64_t));
+    int64_t* dlen = (int64_t*)calloc((size_t)N, sizeof(int64_t));
+    if (!tfm || !dlen) { free(tfm); free(dlen); return 0; }
+    int64_t df[ENGRAM_BM25_MAX_QTOK] = {0};
+    double total_len = 0.0; int64_t live = 0;
+    for (int64_t i = 0; i < N; i++) {
+        EngramNode* n = &g->nodes[i];
+        if (engram_layer_is_transparent(n->layer_id)) continue;
+        live++;
+        int64_t* tf = &tfm[i * nq];
+        engram_field_stats(n->content, qtok, nq, tf, &dlen[i]);
+        engram_field_stats(n->label,   qtok, nq, tf, &dlen[i]);
+        engram_field_stats(n->tags,    qtok, nq, tf, &dlen[i]);
+        total_len += (double)dlen[i];
+        for (int t = 0; t < nq; t++) if (tf[t] > 0) df[t]++;
+    }
+    double avg = (live > 0) ? total_len / (double)live : 1.0;
+    if (avg <= 0.0) avg = 1.0;
+    const double k1 = 1.2, b = 0.75;
+    int64_t nhits = 0;
+    for (int64_t i = 0; i < N; i++) {
+        EngramNode* n = &g->nodes[i];
+        if (engram_layer_is_transparent(n->layer_id)) continue;
+        int64_t* tf = &tfm[i * nq];
+        double s = 0.0;
+        for (int t = 0; t < nq; t++) {
+            if (tf[t] == 0) continue;
+            double idf = log(((double)live - (double)df[t] + 0.5) /
+                             ((double)df[t] + 0.5) + 1.0);
+            double tfd = (double)tf[t];
+            s += idf * (tfd * (k1 + 1.0)) /
+                 (tfd + k1 * (1.0 - b + b * (double)dlen[i] / avg));
+        }
+        if (s > 0.0) {
+            out[nhits].score = s;
+            out[nhits].created = n->created_at;
+            out[nhits].idx = i;
+            nhits++;
+        }
+    }
+    free(tfm); free(dlen);
+    qsort(out, (size_t)nhits, sizeof(EngramHit), engram_hit_cmp);
+    return (nhits < lim) ? nhits : lim;
+}
+
 el_val_t engram_search(el_val_t query, el_val_t limit) {
     EngramStore* g = engram_get();
     const char* q = EL_CSTR(query);
@@ -6833,21 +6979,13 @@ el_val_t engram_search(el_val_t query, el_val_t limit) {
     if (lim <= 0) lim = 100;
     el_val_t lst = el_list_empty();
     if (!q || !*q) return lst;
-    int64_t found = 0;
+    if (g->node_count == 0) return lst;
-    for (int64_t i = 0; i < g->node_count && found < lim; i++) {
+    EngramHit* hits = (EngramHit*)malloc((size_t)g->node_count * sizeof(EngramHit));
-        EngramNode* n = &g->nodes[i];
+    if (!hits) return lst;
-        /* Filter transparent layers: nodes whose layer is `transparent=1`
+    int64_t k = engram_search_ranked(g, q, lim, hits);
-         * shape output but are invisible to introspection ("what do you
+    for (int64_t i = 0; i < k; i++)
-         * know about yourself"). They still surface via engram_activate
+        lst = el_list_append(lst, engram_node_to_map(&g->nodes[hits[i].idx]));
-         * + engram_compile_layered_json — that's the legitimate path. */
+    free(hits);
-        if (engram_layer_is_transparent(n->layer_id)) continue;
-        if (istr_contains(n->content, q) ||
-            istr_contains(n->label,   q) ||
-            istr_contains(n->tags,    q)) {
-            lst = el_list_append(lst, engram_node_to_map(n));
-            found++;
-        }
-    }
     return lst;
 }
 
@@ -7761,28 +7899,42 @@ el_val_t engram_get_node_json(el_val_t id) {
     return el_wrap_str(jb_finish(&b));
 }
 
+/* Look up a node by exact label; returns its JSON or {}. Ported from the
+ * v1.0.0 release runtime — needed by soul.el session continuity
+ * (conv_history_load / session_summary_write / emit_session_start_event). */
+el_val_t engram_get_node_by_label(el_val_t label) {
+    const char* lbl = EL_CSTR(label);
+    if (!lbl || !*lbl) return el_wrap_str(el_strdup(""));
+    EngramStore* g = engram_get();
+    for (int64_t i = 0; i < g->node_count; i++) {
+        EngramNode* n = &g->nodes[i];
+        if (n->label && strcmp(n->label, lbl) == 0) {
+            JsonBuf b; jb_init(&b);
+            engram_emit_node_json(&b, n);
+            return el_wrap_str(b.buf);
+        }
+    }
+    return el_wrap_str(el_strdup(""));
+}
+
 el_val_t engram_search_json(el_val_t query, el_val_t limit) {
+    /* SPEC-SEARCH-UPGRADE 2026-07-14: same ranked BM25+recency core as
+     * engram_search; transparent-layer identity filter enforced inside it. */
     EngramStore* g = engram_get();
     const char* q = EL_CSTR(query);
     int64_t lim = (int64_t)limit;
     if (lim <= 0) lim = 100;
     JsonBuf b; jb_init(&b);
     jb_putc(&b, '[');
-    int first = 1;
+    if (q && *q && g->node_count > 0) {
-    int64_t found = 0;
+        EngramHit* hits = (EngramHit*)malloc((size_t)g->node_count * sizeof(EngramHit));
-    if (q && *q) {
+        if (hits) {
-        for (int64_t i = 0; i < g->node_count && found < lim; i++) {
+            int64_t k = engram_search_ranked(g, q, lim, hits);
-            EngramNode* n = &g->nodes[i];
+            for (int64_t i = 0; i < k; i++) {
-            /* Filter transparent layers — same as engram_search. */
+                if (i) jb_putc(&b, ',');
-            if (engram_layer_is_transparent(n->layer_id)) continue;
+                engram_emit_node_json(&b, &g->nodes[hits[i].idx]);
-            if (istr_contains(n->content, q) ||
-                istr_contains(n->label,   q) ||
-                istr_contains(n->tags,    q)) {
-                if (!first) jb_putc(&b, ',');
-                engram_emit_node_json(&b, n);
-                first = 0;
-                found++;
             }
+            free(hits);
         }
     }
     jb_putc(&b, ']');