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/DATABASE.md

@@ -212,7 +212,7 @@ CREATE TABLE sessions (
 | `transcript_path` | TEXT | YES | Absolute path to the session's JSONL transcript. Written by `routes/hooks.js` on the first event that carries it (subsequent events no-op via a SQL guard) and read by the periodic compaction sweep — so the sweep touches only active session rows instead of scanning the entire `events` table for `json_extract(data,'$.transcript_path')`. Backfilled once from `events` by the `db.js` migration |
 | `source` | TEXT | NO | Data source this session was captured from. `'local'` for this machine's own Claude Code history (the default); otherwise the `remote_sources.id` of the remote SSH machine it was pulled from. Powers the `sources` query filter on `/api/sessions`, `/api/events`, `/api/agents`, `/api/stats`, and `/api/analytics`, and the `sources` facet on `/api/sessions/facets`. Indexed by `idx_sessions_source` |
 | `tool` | TEXT | NO | The AI coding CLI that produced the session. `'claude'` for every hook-created and imported row (the default); `'codex'` for a session ingested from Codex's rollout journals by `server/lib/codex-usage.js` (see `codex_rollouts`) or created by a Codex hook (`tool: "codex"`, `server/lib/codex-hooks.js`) — a Codex session keeps the status its hooks give it while they are current (its newest event at or after its newest journal write minus two minutes); once they stop (removed, untrusted) the journal decides again. A codex row has no `transcript_path`, and, going by the journal, its `status` is `active` only while one of its journals was written in the last two minutes. `'antigravity'` for an agy CLI conversation, ingested by `server/lib/antigravity-usage.js` (see `antigravity_conversations`) or created by an Antigravity hook (`server/lib/antigravity-hooks.js`); no `transcript_path`, and `active` until it has been quiet — no write to its conversation file (or a non-empty `-wal`) or transcript, no hook event — for ten minutes when it has hook events, two minutes when it has none; it then settles to `completed`, its agents too. The startup cleanup of stale `active` sessions and a workspace purge touch only the matching tool's rows (a purge takes the sessions of the workspace's own `tool`). The Workspace's attach/resume list offers `'claude'` rows only |
-| `lane_id` | INTEGER | YES | The workspace that OWNS the session — the only sessions a workspace lists: the lane whose dashboard pane held it, stamped by `bindRunSession` (`server/routes/hooks.js`) from the hook's `run_id` — first writer wins, a nested `claude -p` excluded. NULL for a session no workspace started (a terminal, an import, a tool with no hooks). No FK: removing a workspace leaves its sessions. Backfilled once from `dashboard_runs`. Indexed by `idx_sessions_lane` |
+| `lane_id` | INTEGER | YES | The workspace that OWNS the session — the only sessions a workspace lists: the lane whose dashboard pane held it, stamped by `bindRunSession` (`server/routes/hooks.js`) from the hook's `run_id` — first writer wins, a nested `claude -p` excluded — or, for a Codex/Antigravity session, by `claimToolSessions` (`server/lib/dashboard-runs.js`) from the same-tool run that was live in its folder when it started. NULL for a session no workspace started (a terminal, an import, a tool with no hooks). No FK: removing a workspace leaves its sessions. Backfilled once from `dashboard_runs`. Indexed by `idx_sessions_lane` |
 | `archived_at` | TEXT | YES | When the user archived the session out of its workspace's lists (`PATCH /api/sessions/:id {archived}`). Hides only — nothing is deleted |
 
 **Constraints:**
@@ -607,6 +607,17 @@ CREATE INDEX idx_agents_status ON agents(status);
 -- before inserting; on a subagent-heavy re-import this drops a large sweep from
 -- tens of seconds to sub-second.
 CREATE INDEX idx_events_agent_type ON events(agent_id, event_type);
+
+-- A session's events in insert order. NOT a prefix of idx_events_session_type
+-- (not id-ordered): every hook's duplicate guard reads a session's latest event
+-- through it. Dropping it (ad6e801) made that read sort the whole session per
+-- hook and made a correlated "next tool event" query quadratic — minutes on a
+-- 29k-event session, the event loop frozen for every page.
+CREATE INDEX idx_events_session ON events(session_id, id);
+
+-- Per-tool counts (analytics, workflows) and the events filter's tool list
+-- read this alone instead of every event row (~300 ms -> ~20 ms at 233k rows).
+CREATE INDEX idx_events_tool ON events(tool_name);
 ```
 
 ### tool_executions Indexes