test(qa-observer): fix mode treats atomic temps of authorized src/test writes as transient

CI webhook-fix failed with 'Could not watch test/worker.regression-1.test.ts.tmp...':
Claude Code's Write renamed its temp before the per-file watch was added. The
functional eval now tells the observer its mode, and a temp whose target that
mode may write is observed through its directory watch. Report-only mode and
undeclared paths keep failing closed.

test/helpers/qa-functional-eval.ts

@@ -103,7 +103,7 @@ export async function runQAFunctionalCase(entry: { id: string; family: QAFamily;
     fixtureGit(fixture.root, ['commit', '-m', 'Bind current QA instructions to fixture']);
     fixture.revision = fixtureGit(fixture.root, ['rev-parse', 'HEAD']);
     if (fixtureGit(fixture.root, ['status', '--porcelain'])) throw new Error('QA fixture must start clean');
-    observer = await observeQAWrites(fixture.root, { evidenceProducer: true });
+    observer = await observeQAWrites(fixture.root, { evidenceProducer: true, atomicWriteMode: entry.mode });
     await runRecordedOfficeHoursAttempt({
       collector, name: entry.id, suite: 'Functional QA native E2E',
       model: process.env.EVALS_MODEL ?? resolveEvalModel('capture'),