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

server/openapi.js

@@ -1347,7 +1347,7 @@ function createOpenApiSpec() {
             "Per-table counts from restoring an export bundle. Session-scoped counts are rows newly inserted; sessions_skipped counts sessions already present (skipped whole to stay idempotent).",
           properties: {
             ok: { type: "boolean" },
-            source: { type: "string", description: "Uploaded filename or server-side path read." },
+            source: { type: "string", description: "The uploaded file's name." },
             format: {
               type: "string",
               nullable: true,