chore: the compiler is a build input too, and regenerate under the fixed elc

Installing the fixed compiler exposed a blind spot in this gate. On clean main,
with no source changed, soulc-stamp reported OK while the committed amalgam had
gone stale by a line — because the fingerprint covered .el sources and not the
toolchain that turns them into dist/soul.c. That is exactly the class of silent
divergence the gate was written to close, and it had it.

The stamp now fingerprints the elc binary alongside the sources. Demonstrated: with
the old stamp the gate passed after a compiler swap; with this change the same
condition fails, naming __compiler__.

dist/soul.c regenerated under the installed compiler (1,205,027 bytes) and verified:
builds from its own committed input, the declared principal is present in the
resulting binary, interface 110 routes in / 110 out.

Differential evidence that the new compiler is a strict superset — same sources,
both compilers:
  neuron soul        1 differing line, the el_cgi_init emission
  engram server.el   0 differing lines
  mcp-wrapper        0 differing lines
  mcp-proxy          0 differing lines

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

dist/soul.c

@@ -31938,6 +31938,7 @@ el_val_t layered_cycle(el_val_t raw_input, el_val_t session_id, el_val_t utility
 
 int main(int _argc, char** _argv) {
   el_runtime_init_args(_argc, _argv);
+  el_cgi_init(EL_STR("neuron-soul"), EL_STR("ntn-genesis@http://localhost:7770"), EL_STR("william-christopher-anderson"), EL_STR("dharma-mainnet"), EL_STR("http://localhost:8742"));
   soul_cgi_id_raw = env(EL_STR("SOUL_CGI_ID"));
   soul_cgi_id = ({ el_val_t _if_result_821 = 0; if (str_eq(soul_cgi_id_raw, EL_STR(""))) { _if_result_821 = (EL_STR("ntn-genesis")); } else { _if_result_821 = (soul_cgi_id_raw); } _if_result_821; });
   port_raw = env(EL_STR("NEURON_PORT"));

dist/soul.c.stamp

@@ -1,7 +1,8 @@
 # soul.c.stamp — fingerprint of the .el sources dist/soul.c was generated from.
 # Written by tools/soulc-stamp.sh --write. Do not hand-edit.
-# generated_amalgam_sha256 ee09798ad93ddd047136577cf324483e5956984d60d06596d34662f315ee0df4
-# generated_amalgam_bytes  1204845
+# generated_amalgam_sha256 f251307717d40796a8909154fc7077d3343a0d30e20889b7e9d16f1c4308a888
+# generated_amalgam_bytes  1205027
+7cf5e29d2618db2fca04e6df7aa8954dd6cf9ac5e70aafb8e0b52aa734882131  __compiler__
 f8597e10546654bce3fbbe40461b2da59d0e06dbf1b038d1d362d24f949e3911  awareness.el
 b6f3d14ca0c26017a2d617399a6d3754dabb0905e4d5f52eb75d25c4ad18d3c5  chat.el
 42288c212cbf72fb1e8ecbd4d9900e4e9ee1cfa475b7974295c7637f1bf2939f  elp-input.el

tools/soulc-stamp.sh

@@ -30,9 +30,19 @@ AMALGAM="$ROOT/dist/soul.c"
 
 # Every .el at the repo root is an input to the amalgam. Sorted so the hash is
 # order-independent; content-only so timestamps and checkouts do not perturb it.
+# The COMPILER is an input too. Learned 2026-08-09 by installing a fixed elc and
+# watching this gate report OK while the committed amalgam had gone stale by a line:
+# the sources had not changed, so a source-only fingerprint could not see it. That is
+# precisely the blind spot this gate exists to close, and it had it.
 fingerprint() {
   (
     cd "$ROOT" || exit 1
+    ELC_BIN="${ELC:-$HOME/neuron-dev-stack/src/el/lang/dist/platform/elc}"
+    if [ -f "$ELC_BIN" ]; then
+      printf '%s  %s\n' "$(shasum -a 256 "$ELC_BIN" | awk '{print $1}')" "__compiler__"
+    else
+      printf '%s  %s\n' "MISSING" "__compiler__"
+    fi
     for f in $(ls -1 *.el 2>/dev/null | sort); do
       printf '%s  %s\n' "$(shasum -a 256 "$f" | awk '{print $1}')" "$f"
     done