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>

hh/src/ft.rs

@@ -152,7 +152,7 @@ mod tests {
         let dir = std::env::temp_dir().join(format!("hh-ft-{}", std::process::id()));
         std::fs::create_dir_all(&dir).unwrap();
         let src = dir.join("note.txt");
-        std::fs::write(&src, b"offering to the coven").unwrap();
+        std::fs::write(&src, b"offering to the clergy").unwrap();
 
         let (name, bytes, is_dir) = read_payload(src.to_str().unwrap()).unwrap();
         assert_eq!(name, "note.txt");
@@ -161,7 +161,7 @@ mod tests {
             sha256: sha256_hex(&bytes), dir: false, from: "x".into() };
         let dl = dir.join("dl");
         let out = save(&dl, &offer, &bytes).unwrap();
-        assert_eq!(std::fs::read(&out).unwrap(), b"offering to the coven");
+        assert_eq!(std::fs::read(&out).unwrap(), b"offering to the clergy");
         std::fs::remove_dir_all(&dir).ok();
     }