Restructure: Move 52 files into 7 domain packages

korrektur/ zeugnis/ admin/ compliance/ worksheet/ training/ metrics/
52 shims, relative imports, RAG untouched.

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

klausur-service/backend/zeugnis_api.py

@@ -1,19 +1,4 @@
-"""
-Zeugnis Rights-Aware Crawler — barrel re-export.
-
-All implementation split into:
-  zeugnis_api_sources — sources, seed URLs, initialization
-  zeugnis_api_docs    — documents, crawler, statistics, audit
-
-FastAPI router for managing zeugnis sources, documents, and crawler operations.
-"""
-
-from fastapi import APIRouter
-
-from zeugnis_api_sources import router as _sources_router  # noqa: F401
-from zeugnis_api_docs import router as _docs_router  # noqa: F401
-
-# Composite router (used by main.py)
-router = APIRouter()
-router.include_router(_sources_router)
-router.include_router(_docs_router)
+# Backward-compat shim -- module moved to zeugnis/api.py
+import importlib as _importlib
+import sys as _sys
+_sys.modules[__name__] = _importlib.import_module("zeugnis.api")