fix: Leere Controls (title/objective=None) filtern vor Store

- Batch-Postprocessing: Controls mit title/objective = None/null/"" werden
  gefiltert und nicht gespeichert. Title wird aus Objective abgeleitet falls
  nur Title fehlt.
- _store_control: Pre-store Quality Guard lehnt leere Controls ab
- Verhindert "None"-Controls die durch LLM-Parsing-Fehler entstehen

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

control-pipeline/services/control_generator.py

@@ -1526,9 +1526,22 @@ Gib ein JSON-Array zurueck mit GENAU {len(chunks)} Elementen. Fuer Aspekte ohne
         final: list[Optional[GeneratedControl]] = []
         for i in range(len(batch_items)):
             control = all_controls.get(i)
-            if not control or (not control.title and not control.objective):
+            # Filter empty or invalid controls (LLM returned None/empty)
+            if not control:
                 final.append(None)
                 continue
+            title_invalid = not control.title or control.title.strip().lower() in ("none", "null", "")
+            obj_invalid = not control.objective or control.objective.strip().lower() in ("none", "null", "")
+            if title_invalid and obj_invalid:
+                logger.warning("Leerer Control gefiltert (title=%s, objective=%s) — wird nicht gespeichert",
+                              control.title, control.objective)
+                final.append(None)
+                continue
+            # Clean up "None" strings from LLM
+            if title_invalid:
+                control.title = control.objective[:120] if control.objective else "Unbenannt"
+            if obj_invalid:
+                control.objective = control.title
 
             if control.release_state == "too_close":
                 final.append(control)
@@ -1931,6 +1944,14 @@ Kategorien: {CATEGORY_LIST_STR}"""
 
     def _store_control(self, control: GeneratedControl, job_id: str) -> Optional[str]:
         """Persist a generated control to DB. Returns the control UUID or None."""
+        # Pre-store quality guard — reject empty/invalid controls
+        if not control.title or control.title.strip().lower() in ("none", "null", ""):
+            logger.warning("Rejected control with empty/None title: %s", control.control_id)
+            return None
+        if not control.objective or control.objective.strip().lower() in ("none", "null", ""):
+            logger.warning("Rejected control with empty/None objective: %s — %s", control.control_id, control.title)
+            return None
+
         try:
             # Get framework UUID
             fw_result = self.db.execute(