fix: Fix type errors in entity_service and write_note

- Import SearchService directly instead of using string forward reference
- Add null check for entity.permalink before passing to resolve_entity_id
- Fixes pyright type errors reported by CI

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: Joe P <joe@basicmemory.com>

Author: jope-bm

src/basic_memory/mcp/tools/write_note.py

@@ -164,6 +164,8 @@ async def write_note(
             if "409" in str(e) or "conflict" in str(e).lower() or "already exists" in str(e).lower():
                 logger.debug(f"Entity exists, updating instead permalink={entity.permalink}")
                 try:
+                    if not entity.permalink:
+                        raise ValueError("Entity permalink is required for updates")
                     entity_id = await resolve_entity_id(client, active_project.id, entity.permalink)
                     url = f"/v2/projects/{active_project.id}/knowledge/entities/{entity_id}"
                     response = await call_put(client, url, json=entity.model_dump())

src/basic_memory/services/entity_service.py

@@ -29,6 +29,7 @@
 from basic_memory.services import BaseService, FileService
 from basic_memory.services.exceptions import EntityCreationError, EntityNotFoundError
 from basic_memory.services.link_resolver import LinkResolver
+from basic_memory.services.search_service import SearchService
 from basic_memory.utils import generate_permalink
 
 
@@ -43,7 +44,7 @@ def __init__(
         relation_repository: RelationRepository,
         file_service: FileService,
         link_resolver: LinkResolver,
-        search_service: Optional["SearchService"] = None,
+        search_service: Optional[SearchService] = None,
         app_config: Optional[BasicMemoryConfig] = None,
     ):
         super().__init__(entity_repository)