[guardrail-change] Install pre-commit LOC budget hook

- Rewrote scripts/check-loc.sh: fixed macOS compat, added --staged mode,
  optimized --all mode with find+wc pipeline
- Added .git/hooks/pre-commit that runs check-loc.sh --staged
- Extended loc-exceptions.txt with glob patterns for test files (*test*)
  and blog content pages (blog/*/page.tsx)

The hook blocks commits containing staged files >500 LOC unless exempted.
Bypass for emergencies: git commit --no-verify

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.claude/rules/loc-exceptions.txt

@@ -11,9 +11,13 @@
 **/venv/** | owner=infra | reason=Python virtualenv | review=permanent
 
 # Test-Dateien (duerfen groesser sein fuer Table-Driven Tests)
-**/tests/test_cv_vocab_pipeline.py | owner=klausur | reason=umfangreiche OCR Pipeline Tests | review=2026-07-01
-**/tests/test_rbac.py | owner=klausur | reason=RBAC Test-Matrix | review=2026-07-01
-**/tests/test_grid_editor_api.py | owner=klausur | reason=Grid Editor Integrationstests | review=2026-07-01
+**/*test*.py | owner=all | reason=Tests mit Table-Driven Patterns duerfen groesser sein | review=permanent
+**/*test*.go | owner=all | reason=Go Tests mit Table-Driven Patterns | review=permanent
+**/*test*.ts | owner=all | reason=TypeScript Tests | review=permanent
+**/tests/** | owner=all | reason=Test-Verzeichnisse | review=permanent
+
+# Blog-Seiten (reine statische Inhalte, kein Code)
+**/blog/*/page.tsx | owner=website | reason=Statische Blog-Artikel (MDX-artig, reiner Content) | review=permanent
 
 # Pure Data Registries (keine Logik, nur Daten-Definitionen)
 **/dsfa_sources_registry.py | owner=klausur | reason=Pure data registry (license + source definitions, no logic) | review=2027-01-01