quest: plan making tests fit their timeout on the queue runner

quest/m0/queue-watcher/README.md

@@ -137,6 +137,7 @@ Shared shape, for the children to follow:
 
 - [The other repositories follow](/quest/m0/queue-watcher/follow.md) - quest, rind and rust2 are cut over and landing; waits for a fork PR to land through one of their queues
 - [Harden the queue runners](/quest/m0/queue-watcher/runners.md) - each queue runner runs only its repository's queue workflow, and every outside fork PR needs approval
+- [Tests fit their timeout on the queue runner](/quest/m0/queue-watcher/queue-test-timeouts.md) - the root and Worker suites stop timing out or stalling in merge-group runs, so the queue stops ejecting PRs for them
 - [Daemons prune their logs](/quest/m0/queue-watcher/log-retention.md) - the watcher and gate delete their finished logs after a window, so state stays bounded (4.1 GiB on nixos on 2026-11-04)
 - [Retire the batching gate](/quest/m0/queue-watcher/retire.md) - once no repository lands through `quest land serve`, its batching code and host units go
 

quest/m0/queue-watcher/queue-test-timeouts.md

@@ -0,0 +1,100 @@
+# [L] Tests fit their timeout on the queue runner
+
+## Goal
+
+The root and Worker test suites pass in `merge_group` runs on the queue
+runner without timing out or stalling, so the merge queue stops ejecting PRs
+for tests they don't touch. Each test fits comfortably under its limit for a
+measured reason, rather than through a blanket timeout raise.
+
+## Plan
+
+Decided 2026-11-04 (user, /quest-complete follow-up of
+[moq-dev/quest#481](https://github.com/moq-dev/quest/pull/481)), on the Worker
+route tests alone. Widened to the root suite the same day, when this quest's
+own PR, [moq-dev/quest#497](https://github.com/moq-dev/quest/pull/497), was
+ejected for two root-suite tests although it changes only Markdown.
+
+That day, 10 of 11 failed merge-queue runs failed in tests:
+
+- Worker, 7 runs: `cloudflare/test/projects.test.ts` ("enrolled project
+  observations", four times) and `cloudflare/test/github.test.ts` ("signed
+  GitHub webhooks", three times) exceeded vitest's 5s default, six of them on
+  PRs that didn't touch the Worker
+  ([run 41901538568](https://github.com/moq-dev/quest/actions/runs/41901538568)
+  is one).
+- Root, 3 runs: `test/review.test.ts` timed out twice, "a missing or
+  logged-out reviewer CLI is a usage error" at 5.2s
+  ([run 41905766925](https://github.com/moq-dev/quest/actions/runs/41905766925))
+  and "a reviewer's usage limit exits 3 with its reset, and records no round"
+  at 5.9s; `test/land.test.ts` "host daemon > opens the halt issue when the
+  base fixer's launch was lost" ran 1221s against its 30s limit, both in
+  [run 41924229558](https://github.com/moq-dev/quest/actions/runs/41924229558);
+  and `test/gate.test.ts` "killing stops a command that ignores the request"
+  failed an assertion
+  ([run 41888531939](https://github.com/moq-dev/quest/actions/runs/41888531939)).
+
+The land fixer re-queued each as flaky or handed it back, costing a queue
+slot each time; #481 hit its three-flaky stop rule.
+
+- What should the quest's goal be?
+  - ✅ Fix the root cause: find what makes these tests slow in merge-group
+    runs and make each fit, raising a timeout only where a measured cost
+    justifies it
+  - Rejected: raising the suite's timeout; leaving it to the watcher's flaky
+    handling
+- Which milestone?
+  - ✅ m0, in this epic, since it stalls the merge queue today
+  - Rejected: m1
+
+Implementation guidance:
+
+- It looks environmental, and specific to the queue runner. The queue build
+  runs on `nixos-quest-ci`, which
+  [kixelated/nixos#19](https://github.com/kixelated/nixos/pull/19) added to
+  the maintainer's host
+  ([the cutover](/quest/m0/queue-watcher/follow.md));
+  [Harden the queue runners](/quest/m0/queue-watcher/runners.md) only
+  restricts its access. Every `check` job of the `Check` workflow on main
+  that finished that day, 27 by 23:00 UTC, passed both suites on
+  GitHub-hosted Ubuntu. On base `ba352ea8`, the
+  root suite took 122s there
+  ([run 41924220424](https://github.com/moq-dev/quest/actions/runs/41924220424))
+  while the queue runner took 1590s on it at the same time (run 41924229558),
+  and 125s and 372s in the next queue runs on the same base
+  ([run 41923472254](https://github.com/moq-dev/quest/actions/runs/41923472254),
+  [run 41928750874](https://github.com/moq-dev/quest/actions/runs/41928750874)).
+  In the slow run, `land.test.ts` tests that took 0.5-2.6s in the other two
+  took 12-23s. Measure the host's load and memory pressure during queue builds,
+  and what else runs there, before blaming the tests.
+- Some tests have little headroom even on an idle host.
+  "a reviewer's usage limit exits 3 with its reset, and records no round",
+  added by [moq-dev/quest#471](https://github.com/moq-dev/quest/pull/471),
+  runs four cases in one test, each with its own repository and two `quest`
+  CLI runs: 3.3s of its 5s on a developer machine.
+  [moq-dev/quest#470](https://github.com/moq-dev/quest/pull/470) had just
+  split this file's tests to one `quest review` per variant for that reason.
+  Find such tests by their share of the limit on a
+  quiet host, not by which one timed out last.
+- The `land.test.ts` run is a stall, not slowness: the test takes 0.4s alone,
+  and its 30s timeout fired only at 1221s, so its vitest worker ran no timers
+  for about 20 minutes. Either a synchronous call blocked it, such as the
+  `spawnSync` in `git()` (`src/cli/git.ts`), or the host didn't schedule it.
+- The Worker timeouts look like one test stalling, not a slow suite: in
+  [run 41886648526](https://github.com/moq-dev/quest/actions/runs/41886648526)
+  no other Worker test took over 807ms. Every timed-out test delivers an
+  admitted `pull_request` or `push` webhook, whose route starts `waitUntil`
+  background work (`cloudflare/src/github/webhook.ts`), and in
+  [run 41879887537](https://github.com/moq-dev/quest/actions/runs/41879887537)
+  the next test failed 396ms after the timeout, as if that work outlived its
+  test under `isolate: false`. `github.test.ts` stubs no global `fetch`, so its
+  background reads may reach the network.
+- Earlier rounds: [moq-dev/quest#112](https://github.com/moq-dev/quest/pull/112)
+  shared one workerd across files, and
+  [moq-dev/quest#130](https://github.com/moq-dev/quest/pull/130) moved
+  Miniflare's D1 to `/dev/shm`, both in `cloudflare/vitest.config.ts`.
+  [moq-dev/quest#177](https://github.com/moq-dev/quest/pull/177)'s
+  `scripts/gate-bench.sh` reproduces suite contention, and
+  `just worker-test-isolated` runs each Worker case alone.
+- Verify with repeated runs under the queue runner's conditions, not one
+  green run.