fix(ci): address PR review — filter comments, trim whitespace, warn on missing scripts

Address all review comments from Hoshe and Tyre on PR #27:
- Remove 2>/dev/null from pre-pr-fixtures (critical: swallowed errors)
- Remove dead _file_type function
- Check 4: error on districts with no locations declared
- Check 5: print advisory message when skipping
- Check 8: cross-file line ID uniqueness (not just per-file)
- Check 9: document D-034 asymmetric relationships in docstring
- Document regex fallback rationale in _scan_knowledge
- Add D-035 decision trace to schema descriptions
- Use concrete protocol version in DEVOPS.md example
- Amend D-035 with focused (9th mood) and greeting (14th situation)

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

Makefile

@@ -149,7 +149,7 @@ pre-pr-validate: validate-content check-fact-ids
 
 pre-pr-fixtures:
 	@echo "Checking fixture staleness..."
-	@cd server && cargo test --test gen_fixtures -- --ignored 2>/dev/null
+	@cd server && cargo test --test gen_fixtures -- --ignored
 	@if git diff --quiet client/tests/fixtures/; then \
 		echo "--- Fixtures: UP TO DATE ---"; \
 	else \