fix: add db.rollback() to batch dedup error handlers

SQLAlchemy sessions enter a failed state after SQL errors.
Without rollback(), all subsequent queries on the same session
fail with InFailedSqlTransaction. Added try/except with rollback
in _mark_duplicate, _mark_duplicate_to, _write_review, cross-group
pass, and the main phase1 loop.

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

backend-compliance/compliance/services/batch_dedup_runner.py

@@ -141,6 +141,10 @@ class BatchDedupRunner:
             except Exception as e:
                 logger.error("BatchDedup Phase 1 error on hint %s: %s", hint, e)
                 self.stats["errors"] += 1
+                try:
+                    self.db.rollback()
+                except Exception:
+                    pass
 
         logger.info(
             "BatchDedup Phase 1 done: %d masters, %d linked, %d review",
@@ -372,6 +376,7 @@ class BatchDedupRunner:
                 # Simple check: different control UUID is enough
                 if match_score > LINK_THRESHOLD:
                     # Mark the worse one as duplicate
+                    try:
                         self.db.execute(text("""
                             UPDATE canonical_controls
                             SET release_state = 'duplicate', merged_into_uuid = CAST(:master AS uuid)
@@ -392,6 +397,11 @@ class BatchDedupRunner:
 
                         self.db.commit()
                         cross_linked += 1
+                    except Exception as e:
+                        logger.error("BatchDedup cross-group link error %s→%s: %s",
+                                     uuid, match_uuid, e)
+                        self.db.rollback()
+                        self.stats["errors"] += 1
                     break  # Only one cross-link per control
                 elif match_score > REVIEW_THRESHOLD:
                     self._write_review(
@@ -474,6 +484,7 @@ class BatchDedupRunner:
 
     async def _mark_duplicate(self, master: dict, candidate: dict, confidence: float):
         """Mark candidate as duplicate of master, transfer parent links."""
+        try:
             self.db.execute(text("""
                 UPDATE canonical_controls
                 SET release_state = 'duplicate', merged_into_uuid = CAST(:master AS uuid)
@@ -491,9 +502,15 @@ class BatchDedupRunner:
             self.stats["parent_links_transferred"] += transferred
 
             self.db.commit()
+        except Exception as e:
+            logger.error("BatchDedup _mark_duplicate error %s→%s: %s",
+                         candidate["uuid"], master["uuid"], e)
+            self.db.rollback()
+            raise
 
     async def _mark_duplicate_to(self, master_uuid: str, candidate: dict, confidence: float):
         """Mark candidate as duplicate of a Qdrant-matched master."""
+        try:
             self.db.execute(text("""
                 UPDATE canonical_controls
                 SET release_state = 'duplicate', merged_into_uuid = CAST(:master AS uuid)
@@ -511,6 +528,11 @@ class BatchDedupRunner:
             self.stats["parent_links_transferred"] += transferred
 
             self.db.commit()
+        except Exception as e:
+            logger.error("BatchDedup _mark_duplicate_to error %s→%s: %s",
+                         candidate["uuid"], master_uuid, e)
+            self.db.rollback()
+            raise
 
     def _transfer_parent_links(self, master_uuid: str, duplicate_uuid: str) -> int:
         """Move existing parent links from duplicate to master."""
@@ -549,6 +571,7 @@ class BatchDedupRunner:
 
     def _write_review(self, candidate: dict, matched_payload: dict, score: float):
         """Write a dedup review entry for borderline matches."""
+        try:
             self.db.execute(text("""
                 INSERT INTO control_dedup_reviews
                     (candidate_control_id, candidate_title, candidate_objective,
@@ -569,6 +592,10 @@ class BatchDedupRunner:
                 }),
             })
             self.db.commit()
+        except Exception as e:
+            logger.error("BatchDedup _write_review error: %s", e)
+            self.db.rollback()
+            raise
 
     # ── Progress ─────────────────────────────────────────────────────────