feat(hh): /pw command, RAM-only direnv autostart, robust lets-hack; coven→clergy

- add /pw (alias /password): reveal this room's password locally (never
  broadcast); surfaced in the F1 help overlay and the join hint
- direnv-autostart/: cd-to-launch a single real-user session via direnv;
  password is minted in memory at launch (never written to disk, matching the
  RAM-only model) and scoped to the child process. setup.sh installs direnv,
  hooks bash/zsh, and `direnv allow`s the dir
- lets-hack.sh: boot a FRESH server by default (replacing any live one) with a
  --reuse opt-out; add -h/--help/-help; guard against killing the tmux session
  you're attached to; switch-client into the coven when run inside tmux
- rename coven→clergy across rust/python/scripts; tests/test_coven.py→test_clergy.py
- snapshots in-progress hack-house client work (sandbox, themes, net, ui)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cmd_chat/server/factory.py

@@ -24,7 +24,7 @@ def create_app(password: str = "", name: str = "cmd-chat-server") -> Sanic:
     app.ctx.ws_secret = os.urandom(32)
     app.ctx.admin_token = secrets.token_hex(16)
     app.ctx.rate_limiter = RateLimiter(max_requests=10, window_seconds=60)
-    # Coven capacity. 4 by default; raise via CMD_CHAT_MAX_USERS — infra-for-more,
+    # Clergy capacity. 4 by default; raise via CMD_CHAT_MAX_USERS — infra-for-more,
     # the cap is data not architecture (broadcast fan-out is O(N)).
     app.ctx.max_users = int(os.environ.get("CMD_CHAT_MAX_USERS", "4"))
     app.ctx.cleanup_task = None