fix(sync): use strict deferred relation resolution

src/basic_memory/indexing/batch_indexer.py

@@ -493,8 +493,14 @@ class BatchIndexer:
         async def resolve_relation(relation: Relation) -> int:
             async with semaphore:
                 try:
+                    # strict=True for deferred resolution: only fill in to_id on an
+                    # exact permalink/title/file_path match. Fuzzy fallback would silently
+                    # resolve ambiguous links to whichever entity shares tokens with the
+                    # link text, mismatching this with the sync_service forward-reference
+                    # path and producing confidently-wrong graph edges. See
+                    # sync_service.resolve_forward_references for the same change.
                     resolved_entity = await self.entity_service.link_resolver.resolve_link(
-                        relation.to_name
+                        relation.to_name, strict=True
                     )
                     if resolved_entity is None or resolved_entity.id == relation.from_id:
                         return 0

src/basic_memory/sync/sync_service.py

@@ -1447,7 +1447,16 @@ class SyncService:
                 f"to_name={relation.to_name}"
             )
 
-            resolved_entity = await self.entity_service.link_resolver.resolve_link(relation.to_name)
+            # Use strict=True: deferred resolution should only fill in to_id when an
+            # exact permalink/title/file_path match exists. The fuzzy fallback (search-based
+            # token match) would silently resolve ambiguous links like
+            # `[[overview (state-management/session-execution)]]` to whichever entity shares
+            # the most tokens, polluting the graph with confidently-wrong edges that no
+            # audit catches. Leaving such relations unresolved keeps to_id=NULL so they
+            # surface as forward references and can be fixed by the producer.
+            resolved_entity = await self.entity_service.link_resolver.resolve_link(
+                relation.to_name, strict=True
+            )
 
             # ignore reference to self
             if resolved_entity and resolved_entity.id != relation.from_id: