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/DEPLOYMENT.md

@@ -260,6 +260,8 @@ AGENTHUB_GEMINI_DIR=                    # where agy keeps its data (default ~/.g
 
 # Pricing and saved settings
 AGENTHUB_PRICING_SYNC=                  # 0|false|off disables automatic pricing from LiteLLM (default on)
+AGENTHUB_READ_WORKER=                   # 0 runs heavy aggregates (GET /api/workflows) inline instead of in the read worker (default worker)
+AGENTHUB_READ_TIMEOUT_MS=60000          # a read-worker job past this answers 503 EREADTIMEOUT and gets a fresh worker
 AGENTHUB_SETTINGS_FILE=                 # where dashboard-saved settings persist (default ~/.config/agenthub/settings.env);
                                         # load order: real env > the checkout's .env > this file