Phase 12: Test-Suite (30 pytest-Tests) + CLAUDE.md aktualisiert

tests/:
  conftest.py        - minimale Env-Vars + sys.path-Setup
  test_auth.py       - Magic-Token + JWT Round-Trip (4 Tests)
  test_audit.py      - diff() + _to_json() Helper (8 Tests)
  test_models.py     - Pydantic-Validierung (7 Tests)
  test_source_meta.py - Single Source of Truth Konsistenz (7 Tests)
  test_imports.py    - alle Backend-Module importierbar (4 Tests)

requirements-dev.txt: pytest, ftfy, pyflakes

Tests sind reine Unit-Tests (kein DB-Zugriff, kein HTTP-Server),
laufen in <0.5s, geben sofortiges Catch-Net fuer Syntax/Import-Bugs.

Aufruf: PYTHONPATH=src ./venv/bin/python -m pytest tests/ -v

CLAUDE.md erweitert um:
- Sektion Tests (Framework, Pfad, Ausfuehrung)
- Sektion Phasen-Historie (alle 12 Phasen der Aufraeum-Aktion 2026-05-09
  mit kurzer Erklaerung)

tests/test_imports.py

@@ -0,0 +1,33 @@
+"""Smoke-Test: alle Backend-Module importierbar (Catch-Net fuer Syntax-Errors)."""
+import importlib
+
+
+def test_main_app_imports():
+    import main  # FastAPI app
+    assert hasattr(main, "app")
+
+
+def test_all_routers_importable():
+    """Bei Syntax-Fehlern in einem Router crasht das Ganze - hier fangen wir das ab."""
+    for mod in ("auth", "organizations", "licenses", "users",
+                "dashboard", "sources", "token_usage", "audit"):
+        m = importlib.import_module(f"routers.{mod}")
+        assert hasattr(m, "router"), f"routers/{mod} hat keinen router-Objekt"
+
+
+def test_shared_modules_importable():
+    """src/shared/ muss eigenstaendig importierbar sein (kein sys.path-Hack)."""
+    from shared.source_rules import discover_source, evaluate_feeds_with_claude
+    from shared.services.source_health import run_health_checks
+    from shared.services.source_suggester import generate_suggestions
+    from shared.agents.claude_client import call_claude
+    assert callable(discover_source)
+    assert callable(run_health_checks)
+
+
+def test_helpers_importable():
+    from auth import generate_magic_token, create_token, decode_token
+    from audit import log_action, diff, get_client_ip, row_to_dict
+    from email_utils.sender import send_email
+    from email_utils.templates import portal_magic_link_email, invite_email
+    from source_meta import get_meta, category_label, type_label