Wire test coverage: branch coverage config + CI report

Add [tool.coverage] config (branch coverage, source=pacer_cli, sensible
exclude_lines) and run pytest with --cov in CI (term-missing + xml report).
Coverage is reported, not gated — the total is dragged down by pre-existing
untested modules (reader.py/selection.py 0%, downloader.py 9%), same category
as the ruff backlog; the new governance code is well covered (security 93%,
courts 86%, config 70%, errors 84%). Ignore coverage.xml artifacts.

Author: claude

.github/workflows/ci.yml

@@ -40,8 +40,8 @@ jobs:
       - name: Dangling-code audit (stubs + swallowed excepts)
         run: python tools/audit.py
 
-      - name: Run tests
-        run: pytest tests/ -v --tb=short
+      - name: Run tests (with coverage)
+        run: pytest tests/ -v --tb=short --cov=pacer_cli --cov-report=term-missing --cov-report=xml
 
       - name: Run security review tests
         run: pytest tests/test_security_review.py -v

.gitignore

@@ -35,6 +35,8 @@ ENV/
 # Testing
 .pytest_cache/
 .coverage
+.coverage.*
+coverage.xml
 htmlcov/
 .tox/
 .nox/

pyproject.toml

@@ -67,6 +67,20 @@ packages = ["src/pacer_cli"]
 testpaths = ["tests"]
 pythonpath = ["src"]
 
+[tool.coverage.run]
+source = ["pacer_cli"]
+branch = true
+
+[tool.coverage.report]
+show_missing = true
+exclude_lines = [
+    "pragma: no cover",
+    "if TYPE_CHECKING:",
+    "raise NotImplementedError",
+    "if __name__ == .__main__.:",
+    "\\.\\.\\.",
+]
+
 [tool.ruff]
 line-length = 100
 target-version = "py310"