A full-suite report names a failing test under the file that ran it, never under the last file printed #9523

Why: #9424 filed Full suite red: test/spawn-cell-e2e.test.ts with failures from OAuth, migrations, themes and docs tests, so builders twice found nothing red in that file. failedTests in src/checks/flake.ts gives each (fail) line to the last file.test.ts: header it saw, and bun's closing summary of failures follows the last file printed.

Done:

• [x] failedTests stops giving lines to a file when bun's closing summary starts (the N tests failed: / summary lines), or otherwise only keeps a (fail) line inside its own file's block; a test name it can't place is dropped, not given to a neighbour.
• [x] A test in test/ feeds failedTests a real-shaped bun log: two files, a failure in each, then the closing summary repeating both. Each failure comes back once under its own file. The test fails on today's code.
• [x] reportRed (src/checks/report.ts) files no issue for a file whose own tests all passed.

Files: src/checks/flake.ts, test/ (flake or report test). Risk: the queue's flake detection uses the same parser; its existing tests must stay green. Brief: a builder (checks).

Reviewed pull #9526 at its head: ticked failedTests stops giving lines to a file when bun's closing summary starts (the N tests failed: / summary lines), or otherwise only keeps a (fail) line inside its own file's block; a test name it can't place is dropped, not given to a neighbour.; A test in test/ feeds failedTests a real-shaped bun log: two files, a failure in each, then the closing summary repeating both. Each failure comes back once under its own file. The test fails on today's code.; reportRed (src/checks/report.ts) files no issue for a file whose own tests all passed..