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_mcp.py

@@ -0,0 +1,157 @@
+#!/usr/bin/env python3
+"""
+Neuron MCP server — talk to the local Neuron soul (:7770) from Claude Code.
+
+Stdlib only (no pip deps). stdio transport, newline-delimited JSON-RPC 2.0.
+Exposes:
+  - neuron_chat(message, agentic?)       -> the soul's reply
+  - neuron_search_knowledge(query, limit?) -> lexical knowledge search
+  - neuron_search_memory(query, limit?)    -> memory/recall search
+"""
+import sys, json, urllib.request, urllib.parse
+
+SOUL = "http://127.0.0.1:7770"
+
+
+def _post(path, payload, timeout=180):
+    data = json.dumps(payload).encode()
+    req = urllib.request.Request(SOUL + path, data=data,
+                                 headers={"Content-Type": "application/json"}, method="POST")
+    with urllib.request.urlopen(req, timeout=timeout) as r:
+        return json.loads(r.read().decode("utf-8", "replace"))
+
+
+def _get(path, timeout=30):
+    req = urllib.request.Request(SOUL + path, method="GET")
+    with urllib.request.urlopen(req, timeout=timeout) as r:
+        return r.read().decode("utf-8", "replace")
+
+
+def neuron_chat(args):
+    msg = (args.get("message") or "").strip()
+    if not msg:
+        return "error: message is required"
+    agentic = bool(args.get("agentic", False))
+    try:
+        resp = _post("/api/chat", {"session_id": "", "message": msg, "agentic": agentic})
+    except Exception as e:
+        return f"error talking to Neuron (:7770): {e}"
+    return resp.get("response") or resp.get("reply") or json.dumps(resp)[:2000]
+
+
+def _search(path_tmpl, args):
+    q = (args.get("query") or "").strip()
+    if not q:
+        return "error: query is required"
+    limit = int(args.get("limit", 5))
+    try:
+        raw = _get(path_tmpl.format(q=urllib.parse.quote(q), n=limit))
+    except Exception as e:
+        return f"error searching Neuron: {e}"
+    try:
+        arr = json.loads(raw)
+    except Exception:
+        return raw[:2000]
+    # The soul returns HTTP 200 with a JSON error object (not a list) when a
+    # downstream service is unreachable, e.g. memory recall proxies to :7771.
+    if isinstance(arr, dict):
+        err = str(arr.get("error", "")).lower()
+        if "7771" in err or "connect" in err:
+            return ("memory recall is unavailable: the soul's recall backend "
+                    "(:7771) isn't running. neuron_chat and "
+                    "neuron_search_knowledge still work.")
+        return f"error from Neuron: {arr.get('error') or json.dumps(arr)[:500]}"
+    if not isinstance(arr, list):
+        return str(arr)[:2000]
+    if not arr:
+        return "no results"
+    out = []
+    for n in arr[:limit]:
+        nid = n.get("id", "")
+        content = str(n.get("content", "")).replace("\n", " ")[:300]
+        out.append(f"- [{nid}] {content}")
+    return "\n".join(out)
+
+
+def neuron_search_knowledge(args):
+    return _search("/api/neuron/knowledge/search?q={q}&limit={n}", args)
+
+
+def neuron_search_memory(args):
+    return _search("/api/memories/recall?query={q}&limit={n}", args)
+
+
+TOOLS = [
+    {"name": "neuron_chat",
+     "description": "Send a message to the local Neuron soul and return its reply. Use this to talk to Neuron.",
+     "inputSchema": {"type": "object", "properties": {
+         "message": {"type": "string", "description": "What to say to Neuron"},
+         "agentic": {"type": "boolean", "description": "Use agentic/tool mode (default false)"}},
+         "required": ["message"]}},
+    {"name": "neuron_search_knowledge",
+     "description": "Search Neuron's knowledge base (lexical/keyword match).",
+     "inputSchema": {"type": "object", "properties": {
+         "query": {"type": "string"}, "limit": {"type": "integer"}}, "required": ["query"]}},
+    {"name": "neuron_search_memory",
+     "description": "Search what Neuron remembers (memory recall).",
+     "inputSchema": {"type": "object", "properties": {
+         "query": {"type": "string"}, "limit": {"type": "integer"}}, "required": ["query"]}},
+]
+HANDLERS = {"neuron_chat": neuron_chat,
+            "neuron_search_knowledge": neuron_search_knowledge,
+            "neuron_search_memory": neuron_search_memory}
+
+
+def send(msg):
+    sys.stdout.write(json.dumps(msg) + "\n")
+    sys.stdout.flush()
+
+
+def main():
+    for line in sys.stdin:
+        line = line.strip()
+        if not line:
+            continue
+        try:
+            req = json.loads(line)
+        except Exception:
+            continue
+        mid = req.get("id")
+        method = req.get("method")
+        if method == "initialize":
+            pv = (req.get("params") or {}).get("protocolVersion") or "2024-11-05"
+            send({"jsonrpc": "2.0", "id": mid, "result": {
+                "protocolVersion": pv,
+                "capabilities": {"tools": {}},
+                "serverInfo": {"name": "neuron", "version": "0.1.0"}}})
+        elif method == "notifications/initialized":
+            pass
+        elif method == "ping":
+            send({"jsonrpc": "2.0", "id": mid, "result": {}})
+        elif method == "tools/list":
+            send({"jsonrpc": "2.0", "id": mid, "result": {"tools": TOOLS}})
+        elif method == "tools/call":
+            params = req.get("params") or {}
+            name = params.get("name")
+            args = params.get("arguments") or {}
+            fn = HANDLERS.get(name)
+            if not fn:
+                send({"jsonrpc": "2.0", "id": mid, "result": {
+                    "content": [{"type": "text", "text": f"unknown tool: {name}"}], "isError": True}})
+            else:
+                try:
+                    text = fn(args)
+                except Exception as e:
+                    text = f"error: {e}"
+                send({"jsonrpc": "2.0", "id": mid, "result": {
+                    "content": [{"type": "text", "text": str(text)}]}})
+        elif mid is not None:
+            send({"jsonrpc": "2.0", "id": mid,
+                  "error": {"code": -32601, "message": f"method not found: {method}"}})
+
+
+if __name__ == "__main__":
+    try:
+        main()
+    except (BrokenPipeError, KeyboardInterrupt):
+        pass