chore: register repository governance baseline

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a03397-4d51-7fd1-8ff2-946eb22ea2bc

.claude/rules/architecture.md

@@ -0,0 +1,21 @@
+## Architecture
+
+- `store.py` owns SQLite messages, leases, endpoints, and schema migration.
+- `service.py` exposes the authenticated local Unix-socket protocol and runs
+  endpoint-scoped delivery polling.
+- `tmux.py` owns tmux endpoint/session lifecycle; `control.py` owns tmux control
+  mode and injection.
+- `ptytap.py` transparently proxies the agent PTY while `routing.py` observes
+  complete input lines for direct repository addressing.
+- `broker.py` connects observed routing intent to durable queue state and
+  control-mode delivery.
+- `cli.py` is the operator surface for lifecycle, messaging, inspection,
+  replay/export, purging, completion, and diagnostics.
+
+The terminal boundary has three layers: tmux for topology/output, the broker
+for identity and durable intent, and `tamq tap` for full-duplex input
+observation. Preserve that separation when adding coordination-engine support.
+
+## Quick Reference
+
+`~/state-hub/mcp_server/TOOLS.md` — MCP tool reference