fix(report): keep monthly KP headings and readable timing sources

Heading-ensure only covered empty packets, so present KP months still dropped MD/AD titles and sanitizer blanked source_path. Also lock the quality gate onto the new contracts.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_timing_precision_contract.py

@@ -26,6 +26,12 @@ def test_timing_contract_preserves_dates_but_caps_claim_status() -> None:
     assert contract["promotion_gate"]["status"] == "blocked"
 
 
+def test_quality_gate_runs_this_file() -> None:
+    from scripts.run_quality_gate import CORE_PYTEST_TARGETS
+
+    assert "tests/test_timing_precision_contract.py" in CORE_PYTEST_TARGETS
+
+
 def test_empty_timing_contract_still_exposes_boundary() -> None:
     contract = build_timing_precision_contract()
     assert contract["timing_precision"] == "broad_window_only"