perf: parallelize tests and reduce timeouts

- Increase workers from 1 to 10 in CI for parallel execution
- Reduce expect timeout from 5000ms to 2000ms
- Reduce all waitForTimeout calls >1000ms to 200-500ms
- Remove unnecessary waits in global setup

e2e/schedule-tab.test.ts

@@ -175,7 +175,7 @@ test.describe.serial('Issue #7: Schedule Tab', () => {
     await page.click('button:has-text("Generate Schedule")');
 
     // Wait for success message or page reload
-    await page.waitForTimeout(3000);
+    await page.waitForTimeout(500);
 
     // Verify rounds were created in database
     const rounds = await prisma.tournamentRound.findMany({