fix: event-loop freezes, plugin-install boot crash, tmux attach/scrollbar, Codex transcripts

- GET /api/workflows: one LEAD() window pass in a read worker (read-pool.js,
  workflow-stats.js); idx_events_session restored, idx_events_tool added
- compat-sqlite gains function/pluck/readonly so a plugin install without a
  better-sqlite3 build boots again; antigravity-usage uses db.js's Database
- install-hooks adds no checkout hooks while the agenthub plugin is enabled
  (events were doubled)
- terminal attach runs the live tmux server's own binary; the pane scrollbar
  gets a visible 2-column style, and claude panes start with
  CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN=1 so tmux keeps history to scroll
- Codex sessions' conversation in GET /api/sessions/:id/transcript
- Codex/Antigravity sessions claimed by their workspace without hooks
- UI-audit follow-ups, docs and OpenAPI

docs/HOOKS.md

@@ -168,8 +168,12 @@ npm run install-hooks
 > `~/.claude/settings.json.agenthub-bak`) — and since v1.6.17 a settings file that
 > still carries them also blocks the bootstrap's fast path (`hasLegacyHooks`),
 > because the strip runs only in the full pass and a healthy install skipped it
-> every session, keeping the duplicates alive indefinitely. `install-hooks.js` warns when it detects
-> a plugin install, and `/agenthub-doctor` reports any duplicates that remain. See
+> every session, keeping the duplicates alive indefinitely. And `install-hooks.js` itself —
+> run by hand or by every checkout server start (`npm run dev`, `npm start`) — adds nothing
+> while settings.json enables `agenthub@…` and removes every `hook-handler.js` entry it finds
+> instead (same backup); it used to put them straight back after each strip, so a dev server
+> beside the plugin kept ~40% of events doubled. Settings reports such hooks as installed
+> (`source: "plugin"`). `/agenthub-doctor` reports any duplicates that remain. See
 > [PLUGINS.md](PLUGINS.md).
 
 > [!IMPORTANT]