feat: add module-aware test impact analysis and fix CI test scope

Add run_affected_tests.py script that uses module dependency graph to
run only tests for changed modules and their dependents. Fix CI and
Makefile to use pyproject.toml testpaths (was missing 9 of 18 modules).

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

.gitea/workflows/ci.yml

@@ -74,7 +74,7 @@ jobs:
         run: uv pip install --system -r requirements.txt -r requirements-test.txt
 
       - name: Run tests
-        run: python -m pytest tests/ -v --tb=short
+        run: python -m pytest -v --tb=short
 
   validate:
     runs-on: ubuntu-latest