feat(cli): Claude-as-Neuron CLI tooling + soul-side handoff

Tooling built on Tim's machine to run Neuron from the terminal as a
Claude Code session (identity + graph memory + agency) instead of
relaying to the soul's /api/chat.

- cli/neuron_recall.py    BM25 read over the engram snapshot + CLI memories
                          (works around pinned-only soul search)
- cli/neuron_remember.py  reliable local memory writes with read-back verify
                          (works around the corrupting capture endpoint)
- cli/neuron-chat.py      standalone direct-chat REPL with per-turn memory injection
- cli/neuron_mcp.py       stdlib MCP server (chat/search) with graceful degradation
- cli/CLAUDE.md.example   the operating identity that makes Claude Code run as Neuron
- cli/HANDOFF.md          soul-side bugs to fix so this becomes unnecessary

Scaffolding/proposal - intended to be retired once the soul does native
retrieval, correct persistence, and a real CLI identity/voice surface.
Pairs with the runtime model-passthrough + UTF-8 fixes in the el repo.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

cli/neuron_remember.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+"""
+neuron_remember — Neuron's memory write path (save as you go).
+
+Appends a memory to ~/.neuron/neuron-cli-memories.jsonl, a reliable local store
+that neuron_recall.py indexes alongside the graph. Used because the soul's own
+capture path corrupts/loses writes. These can later be synced into the engram
+graph once the soul's write path is fixed.
+
+Usage:
+  python3 ~/neuron_remember.py "Tim prefers X because Y" lesson
+  python3 ~/neuron_remember.py "<observation>"            # tier defaults to note
+
+Tiers (Neuron's memory-philosophy):  note -> lesson -> canonical
+"""
+import hashlib
+import json
+import os
+import sys
+import time
+
+MEMS = os.path.expanduser("~/.neuron/neuron-cli-memories.jsonl")
+VALID_TIERS = ("note", "lesson", "canonical")
+
+
+def main():
+    if len(sys.argv) < 2 or not sys.argv[1].strip():
+        print("usage: neuron_remember.py \"<observation>\" [note|lesson|canonical]")
+        return 1
+    content = sys.argv[1].strip()
+    tier = sys.argv[2].strip().lower() if len(sys.argv) > 2 else "note"
+    if tier not in VALID_TIERS:
+        tier = "note"
+
+    ts = int(time.time())
+    mid = "ncli-" + hashlib.sha1(f"{ts}:{content}".encode()).hexdigest()[:12]
+    rec = {"id": mid, "ts": ts, "tier": tier, "content": content}
+
+    os.makedirs(os.path.dirname(MEMS), exist_ok=True)
+    # dedupe: skip if identical content already saved
+    if os.path.exists(MEMS):
+        for line in open(MEMS, encoding="utf-8", errors="replace"):
+            try:
+                if json.loads(line).get("content") == content:
+                    print(f"(already remembered: {mid})")
+                    return 0
+            except Exception:
+                pass
+    with open(MEMS, "a", encoding="utf-8") as f:
+        f.write(json.dumps(rec, ensure_ascii=False) + "\n")
+
+    # read-back verify (never claim a save that didn't land)
+    ok = any(json.loads(l).get("id") == mid
+             for l in open(MEMS, encoding="utf-8", errors="replace") if l.strip())
+    total = sum(1 for l in open(MEMS, encoding="utf-8", errors="replace") if l.strip())
+    print(f"{'saved' if ok else 'FAILED'} [{tier}] {mid}  (neuron memories: {total})")
+    return 0 if ok else 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())