fix(code-reviews): drain stuck pending queues

[alex-alecu]

Why

Pending code reviews could wait a long time after a slot opened. They only woke up when another event arrived, so some reviews stayed parked even though work could continue.

What changed

This adds a scheduled queue sweep that wakes owners with reviews ready to try again. It reserves capacity safely before the slow work starts, so overlapping events do not take more slots than allowed. Old queued claims can recover again, and old running reviews are only shown as a warning signal, not failed automatically. The admin code review page now shows a live queue health card so support can see waiting work right away.

How to test

1. Open /admin/code-reviews as an admin and confirm Current queue health appears above the older telemetry cards.
2. Create or seed a pending review for an owner with free review capacity, then call the cron endpoint with the configured bearer secret and confirm the review moves toward dispatch.
3. Seed a queued review older than five minutes and confirm the scheduled drain can pick it up again.
4. Seed a running review older than ninety minutes and confirm it is shown in queue health but is not marked failed by the drain.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Executive Summary

All previously flagged issues have been addressed; the only new change since the last review is a vercel.json cron schedule fix (every-minute → every-10-minutes for dispatch-pending-code-reviews).

Previous Issues (all resolved)

File	Issue	Status
apps/web/src/lib/code-reviews/dispatch/dispatch-pending-reviews.ts	pending count misreported error-thrown dispatches as pending	Fixed in abb6338c2
apps/web/src/lib/code-reviews/dispatch/dispatch-pending-code-review-owners.ts	Redundant async/await wrapper in pLimit call	Fixed in 395834f36
apps/web/src/lib/code-reviews/dispatch/dispatch-pending-code-review-owners.ts	Recovery path when bot creation failed during config	Fixed in a9cf55d62
apps/web/src/routers/admin-code-reviews-router.ts:216	Aggregate query could restrict base scan to live queue	Fixed in 134c66820
apps/web/src/lib/code-reviews/db/code-reviews.ts:253	Minute cron avoiding grouping/sorting whole table	Fixed in fee6591f4
apps/web/src/lib/code-reviews/db/code-reviews.ts:223	active_work CTE encoding duplicated condition	Fixed in e70fbf8a4
apps/web/src/routers/admin-code-reviews-router.ts:183	waitingOwnerCondition shared filter	Fixed in 262bea245

Files Reviewed (19 files)

• apps/web/src/app/admin/api/code-reviews/hooks.ts
• apps/web/src/app/admin/code-reviews/page.tsx
• apps/web/src/app/admin/components/CodeReviewQueueHealthSummary.test.ts
• apps/web/src/app/admin/components/CodeReviewQueueHealthSummary.tsx
• apps/web/src/app/api/cron/dispatch-pending-code-reviews/route.test.ts
• apps/web/src/app/api/cron/dispatch-pending-code-reviews/route.ts
• apps/web/src/lib/code-reviews/db/code-reviews.ts
• apps/web/src/lib/code-reviews/dispatch/dispatch-constants.ts
• apps/web/src/lib/code-reviews/dispatch/dispatch-pending-code-review-owners.test.ts
• apps/web/src/lib/code-reviews/dispatch/dispatch-pending-code-review-owners.ts
• apps/web/src/lib/code-reviews/dispatch/dispatch-pending-reviews.test.ts
• apps/web/src/lib/code-reviews/dispatch/dispatch-pending-reviews.ts
• apps/web/src/routers/admin-code-reviews-router.test.ts
• apps/web/src/routers/admin-code-reviews-router.ts
• apps/web/vercel.json
• packages/db/src/migrations/0136_neat_lady_deathstrike.sql
• packages/db/src/migrations/0137_redundant_doctor_spectrum.sql
• packages/db/src/migrations/0138_dry_korath.sql
• packages/db/src/schema.ts

---

_{Reviewed by claude-4.6-sonnet-20260217 · 904,209 tokens}

_{Review guidance: REVIEW.md from base branch main}

[alex-alecu]

Manual test passed.

Tested:

• Opened /admin/code-reviews as a local admin; the Current queue health card rendered and reflected seeded pending, stale queued, and stale-running queue state before and after refresh.
• Called /api/cron/dispatch-pending-code-reviews without auth (401) and with the configured bearer secret (200); the authorized drain considered 2 owners and dispatched 2 reviews.

Verified:

• A pending review and a queued claim older than five minutes were re-reserved and handed to the local code-review worker, which accepted both dispatches.
• Persisted queue state recorded replacement reservation IDs and attempt rows, while a running review older than ninety minutes stayed running; queue-health counts dropped pending/stale queued to zero while retaining the stale-running diagnostic.