fix(ci): exclude flaky performance tests from CI

Performance tests use timing-sensitive assertions (e.g., for-each must
complete within 1.5x of static parallel) that fail intermittently on
shared CI runners. The test file is already marked with
@pytest.mark.performance — just add it to the CI exclusion filter
alongside real_api tests.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Jason Robert

.github/workflows/ci.yml

@@ -110,11 +110,12 @@ jobs:
 
       - name: Run tests with coverage
         timeout-minutes: 10
-        run: uv run pytest --cov=src/conductor --cov-report=xml --cov-report=term-missing -m "not real_api"
+        run: uv run pytest --cov=src/conductor --cov-report=xml --cov-report=term-missing -m "not real_api and not performance"
         env:
           # Fake API key for mock tests to prevent accidental real API calls.
           # Real API tests (marked with @pytest.mark.real_api) are excluded from CI
-          # via the '-m "not real_api"' filter and must be run manually with valid key.
+          # via the marker filter. Performance tests are also excluded as they
+          # contain timing-sensitive assertions that are flaky on shared CI runners.
           # This ensures CI tests are fast, free, and don't leak credentials.
           ANTHROPIC_API_KEY: "sk-ant-test-fake-key-for-mocking"