feat: Batch Dedup Runner — 85k→~18-25k Master Controls

Adds batch orchestration for deduplicating ~85k Pass 0b atomic controls
into ~18-25k unique masters with M:N parent linking.

New files:
- migrations/078_batch_dedup.sql: merged_into_uuid column, perf indexes,
  link_type CHECK extended for cross_regulation
- batch_dedup_runner.py: BatchDedupRunner with quality scoring, merge-hint
  grouping, title-identical short-circuit, parent-link transfer, and
  cross-regulation pass
- tests/test_batch_dedup_runner.py: 21 tests (all passing)

Modified:
- control_dedup.py: optional collection param on Qdrant functions
- crosswalk_routes.py: POST/GET batch-dedup endpoints

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

backend-compliance/compliance/services/control_dedup.py

@@ -317,10 +317,12 @@ async def qdrant_search(
     embedding: list[float],
     pattern_id: str,
     top_k: int = 10,
+    collection: Optional[str] = None,
 ) -> list[dict]:
     """Search Qdrant for similar atomic controls, filtered by pattern_id."""
     if not embedding:
         return []
+    coll = collection or QDRANT_COLLECTION
     body: dict = {
         "vector": embedding,
         "limit": top_k,
@@ -334,7 +336,7 @@ async def qdrant_search(
     try:
         async with httpx.AsyncClient(timeout=10.0) as client:
             resp = await client.post(
-                f"{QDRANT_URL}/collections/{QDRANT_COLLECTION}/points/search",
+                f"{QDRANT_URL}/collections/{coll}/points/search",
                 json=body,
             )
             if resp.status_code != 200:
@@ -349,6 +351,7 @@ async def qdrant_search(
 async def qdrant_search_cross_regulation(
     embedding: list[float],
     top_k: int = 5,
+    collection: Optional[str] = None,
 ) -> list[dict]:
     """Search Qdrant for similar controls across ALL regulations (no pattern_id filter).
 
@@ -356,6 +359,7 @@ async def qdrant_search_cross_regulation(
     """
     if not embedding:
         return []
+    coll = collection or QDRANT_COLLECTION
     body: dict = {
         "vector": embedding,
         "limit": top_k,
@@ -364,7 +368,7 @@ async def qdrant_search_cross_regulation(
     try:
         async with httpx.AsyncClient(timeout=10.0) as client:
             resp = await client.post(
-                f"{QDRANT_URL}/collections/{QDRANT_COLLECTION}/points/search",
+                f"{QDRANT_URL}/collections/{coll}/points/search",
                 json=body,
             )
             if resp.status_code != 200:
@@ -380,10 +384,12 @@ async def qdrant_upsert(
     point_id: str,
     embedding: list[float],
     payload: dict,
+    collection: Optional[str] = None,
 ) -> bool:
-    """Upsert a single point into the atomic_controls Qdrant collection."""
+    """Upsert a single point into a Qdrant collection."""
     if not embedding:
         return False
+    coll = collection or QDRANT_COLLECTION
     body = {
         "points": [{
             "id": point_id,
@@ -394,7 +400,7 @@ async def qdrant_upsert(
     try:
         async with httpx.AsyncClient(timeout=10.0) as client:
             resp = await client.put(
-                f"{QDRANT_URL}/collections/{QDRANT_COLLECTION}/points",
+                f"{QDRANT_URL}/collections/{coll}/points",
                 json=body,
             )
             return resp.status_code == 200
@@ -403,27 +409,31 @@ async def qdrant_upsert(
         return False
 
 
-async def ensure_qdrant_collection(vector_size: int = 1024) -> bool:
-    """Create the Qdrant collection if it doesn't exist (idempotent)."""
+async def ensure_qdrant_collection(
+    vector_size: int = 1024,
+    collection: Optional[str] = None,
+) -> bool:
+    """Create a Qdrant collection if it doesn't exist (idempotent)."""
+    coll = collection or QDRANT_COLLECTION
     try:
         async with httpx.AsyncClient(timeout=10.0) as client:
             # Check if exists
-            resp = await client.get(f"{QDRANT_URL}/collections/{QDRANT_COLLECTION}")
+            resp = await client.get(f"{QDRANT_URL}/collections/{coll}")
             if resp.status_code == 200:
                 return True
             # Create
             resp = await client.put(
-                f"{QDRANT_URL}/collections/{QDRANT_COLLECTION}",
+                f"{QDRANT_URL}/collections/{coll}",
                 json={
                     "vectors": {"size": vector_size, "distance": "Cosine"},
                 },
             )
             if resp.status_code == 200:
-                logger.info("Created Qdrant collection: %s", QDRANT_COLLECTION)
+                logger.info("Created Qdrant collection: %s", coll)
                 # Create payload indexes
                 for field_name in ["pattern_id", "action_normalized", "object_normalized", "control_id"]:
                     await client.put(
-                        f"{QDRANT_URL}/collections/{QDRANT_COLLECTION}/index",
+                        f"{QDRANT_URL}/collections/{coll}/index",
                         json={"field_name": field_name, "field_schema": "keyword"},
                     )
                 return True
@@ -710,6 +720,7 @@ class ControlDedupChecker:
         action: str,
         obj: str,
         pattern_id: str,
+        collection: Optional[str] = None,
     ) -> bool:
         """Index a new atomic control in Qdrant for future dedup checks."""
         norm_action = normalize_action(action)
@@ -730,4 +741,5 @@ class ControlDedupChecker:
                 "object_normalized": norm_object,
                 "canonical_text": canonical,
             },
+            collection=collection,
         )