v0.18.133 — inbox RUM boot marks for FCP diagnosis

Performance

• Inbox RUM boot marks for FCP diagnosis (BORD-995 remaining instrumentation). Client now emits the allowlisted marks that already passed both RUM layers (route + DB adapter) but had zero call sites: shell_rendered, list_rendered, conversation_open, thread_shell_rendered, thread_hydrated, cache_paint. Each carries total_ms from navigationStart (same clock as inbox_mount) so waterfalls vs FCP are possible. Warm Dexie apply fires cache_paint + thread_hydrated; network apply keeps inbox_thread_direct_fetch / inbox_thread_state_apply and also emits thread_hydrated. Gate flooding inbox_render_model (~0ms median) to duration ≥ 8ms or ~1% sample.

Verification

• pnpm --filter app exec vitest run lib/inbox-boot-marks.test.ts lib/inbox-performance.test.ts components/inbox/use-conversation-cache-effect.test.ts app/api/telemetry/performance/route.test.ts
• pnpm --filter @repo/database exec vitest run src/adapters/client-performance.test.ts
• cd apps/app && npx tsc --noEmit