fix(test): strip every inherited CODEMAN_* var and move quick-start off 3099 (#479)

Split out of #476. A Docker Compose deployment exports CODEMAN_CASES_PATH,
which bypasses the temp HOME, so route tests wrote into the real case root.


Claude-Session: https://claude.ai/code/session_01GuHtuPiHXdykq9T6rKQJ9n

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

test/quick-start.test.ts

@@ -4,7 +4,7 @@ import { existsSync, rmSync, mkdirSync, mkdtempSync } from 'node:fs';
 import { join } from 'node:path';
 import { tmpdir } from 'node:os';
 
-const TEST_PORT = 3099;
+const TEST_PORT = 3299;
 const ORIGINAL_HOME = process.env.HOME;
 const TEST_HOME = mkdtempSync(join(tmpdir(), 'codeman-quick-start-'));
 const CASES_DIR = join(TEST_HOME, 'codeman-cases');
@@ -33,7 +33,7 @@ describe('Quick Start API', () => {
     server = await createTestServer(TEST_PORT);
     await server.start();
     baseUrl = `http://localhost:${TEST_PORT}`;
-  });
+  }, 30000);
 
   afterEach(() => {
     // Clean up cases created during this test