test(bd-129): fix flaky integration test by skipping test worker files

The test was reading the first 20 log files alphabetically, which were all
-test-worker-* files containing only `worker.booting` events. This caused
the test to fail when expecting at least 2 distinct event types.

Changes:
- Filter out `-test-worker-*` files when sampling log files
- Increase sample size from 20 to 50 files for better coverage

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/parser.real-logs.integration.test.ts

@@ -426,8 +426,8 @@ describe('Real NEEDLE Log Integration', () => {
 
     it('should cover multiple distinct event types across files', () => {
       const files = readdirSync(logsDir)
-        .filter((f) => f.endsWith('.jsonl'))
-        .slice(0, 20);
+        .filter((f) => f.endsWith('.jsonl') && !f.startsWith('-test-worker-'))
+        .slice(0, 50);
 
       const eventTypes = new Set<string>();
       for (const file of files) {