test: resolve the thin-test item, decline the runner merge

Item 4 of the test-suite review:

- Delete TestEmitWithNoObserversIsNoop (no assertion; ranging a nil slice
  cannot panic) and TestStoreReturnsWiredStore (a getter returning its
  own field).
- Collapse the four TestFilteredJobIndexes* tests into one table-driven
  TestFilteredJobIndexes, matching TestFilterValue above it.
- Replace the TestMainViewBuilds smoke test with
  TestMainViewRecordStartupAddsHistoryRow, which calls the recordStartup
  closure for both wordings run.go selects between and asserts the rows
  reach the History table through its own cell callbacks. Keeps the
  unique coverage the review identified and adds the !windowShown branch.

Item 5 is declined with measurements: the three RunJob tests cost 0.14 s
combined, so merging them saves ~90 ms while forcing their three
fixtures (including the only Manual trigger) into one. The runner
package's runtime is the two timeout tests, not subprocess spawns.

go vet and go test -race pass for src/app and src/ui.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/TEST_REVIEW_PLAN.md

@@ -84,26 +84,34 @@ go test -coverpkg=./src/domain,./src/storage,./src/runner,./src/scheduler,./src/
 None of these is wrong; each is close enough to worthless that it should be
 either justified or removed. Grouped because they want one decision, not four.
 
-- [ ] `TestEmitWithNoObserversIsNoop`
+- [x] `TestEmitWithNoObserversIsNoop`
       ([events_test.go:36](../src/app/events_test.go)) — the only test in the
       suite with no assertion at all. Ranging over a nil slice cannot panic in
       Go, so it pins nothing. Delete.
-- [ ] `TestStoreReturnsWiredStore`
+- [x] `TestStoreReturnsWiredStore`
       ([service_test.go:51](../src/app/service_test.go)) — asserts that a
       one-line getter returns its own field. Delete.
-- [ ] `TestMainViewBuilds`
+- [x] `TestMainViewBuilds`
       ([mainwindow_test.go:72](../src/ui/mainwindow_test.go)) — a smoke test;
       `TestMainViewFitsTheDefaultWindowSize` builds the same view. Its only
       unique coverage is `w.SetContent(content)` and `recordStartup(0, true)`.
       Either fold those two calls into the sizing test and delete this one, or
       keep it and say in its comment that `recordStartup` is what it is for.
-- [ ] `TestFilteredJobIndexesAll` / `ByNamedFolder` / `NoFolder` / `EmptySlice`
+
+      Done as neither: folding an assertionless `recordStartup` call into the
+      sizing test would have put unrelated work inside an F1/F3 regression
+      guard. It became `TestMainViewRecordStartupAddsHistoryRow`, which calls
+      the closure for both wordings `run.go` selects between and asserts the
+      two rows arrive in the History table, read back through the table's own
+      cell callbacks so the refresh is proved too. Same unique coverage, plus
+      the previously uncovered `!windowShown` branch.
+- [x] `TestFilteredJobIndexesAll` / `ByNamedFolder` / `NoFolder` / `EmptySlice`
       ([jobs_view_test.go:59-101](../src/ui/jobs_view_test.go)) — four tests
       over one small pure function. Collapse into one table-driven test in the
       style of `TestFilterValue` directly above them; the `EmptySlice` case
       becomes one row rather than a function.
 
-## 5. Runtime cost of the runner tests (optional)
+## 5. Runtime cost of the runner tests — declined, with measurements
 
 `TestRunJobLogFileAllHeaders`, `TestRunJobRecordFields`, and
 `TestRunJobWritesLogFile` ([runner_test.go](../src/runner/runner_test.go)) have
@@ -111,9 +119,28 @@ identical coverage profiles but assert three genuinely different things — log
 headers, `RunRecord` field values, and the log file's name and directory. They
 are **not** duplicates and should not be deleted on that basis.
 
-The cost is that each spawns a real subprocess; the `runner` package takes 5.3 s.
-If suite wall time becomes a concern, merge them into one `RunJob` call with
-three assertion blocks. Until then, leave them alone.
+- [x] Decided: **do not merge them.** The premise was wrong. Per-test timings
+      from `go test -count=1 -v ./src/runner`:
+
+      | Test | Time |
+      |---|---|
+      | `TestRunJobTimesOut` | 2.10 s |
+      | `TestRunJobZeroTimeoutMeansNoTimeout` | 1.05 s |
+      | `TestRunJobWritesLogFile` | 0.05 s |
+      | `TestRunJobLogFileAllHeaders` | 0.05 s |
+      | `TestRunJobRecordFields` | 0.04 s |
+
+      The three candidates cost 0.14 s combined, so the merge buys back about
+      90 ms. The package's runtime is the two deliberate waits in the timeout
+      tests plus build time — subprocess spawn is not what makes `runner` slow.
+      Against that, the three fixtures differ in ways the assertions read:
+      `TestRunJobWritesLogFile` runs the `Manual` trigger, the other two run
+      `Schedule`, and each uses its own job ID and name. Merging forces one
+      fixture and drops the `Manual` path from the log-header assertions — the
+      exact silent loss this item warned about, for 90 ms.
+
+      If `runner` wall time ever does become a problem, the two timeout tests
+      are where the seconds are.
 
 ## Explicitly not changing
 
@@ -142,7 +169,7 @@ Recorded here so a later pass does not re-report them:
 2. Item 3 (`itoa`) — independent of everything else.
 3. Item 1 (deletions) — one commit, with the coverage re-run as evidence.
 4. Item 4 (thin tests) — needs a judgment call per test.
-5. Item 5 — only if suite wall time becomes a problem.
+5. Item 5 — measured and declined; see the item.
 
 Items 1 and 4 change the test inventory, so [TESTS.md](TESTS.md) has to be
 updated in the same commit. No [CHANGELOG.md](CHANGELOG.md) entry is needed: