Refactor OpenViking Memory API and User Management

- Updated API authentication headers to use `X-API-Key` for both admin and user APIs.
- Modified the account creation process to directly create user-specific accounts without requiring an admin workspace.
- Enhanced user creation to return account-specific details, including `admin_user_id`.
- Introduced new endpoints for retrieving task status and user profiles, allowing for more flexible user data management.
- Updated search functionality to include additional parameters such as `level` and `score_threshold`.
- Improved the handling of user keys in the storage layer to associate them with specific accounts.
- Added tests to validate the new user account creation process and search functionalities, ensuring proper integration with the OpenViking service.
- Included new documentation to reflect changes in API usage and expected request/response formats.

memory_system_api/store.py

@@ -65,7 +65,7 @@ class OpenVikingUserKeyStore:
                 ).fetchone()
         return str(row[0]) if row else None
 
-    def save_user_key(self, user_id: str, user_key: str) -> None:
+    def save_user_key(self, user_id: str, user_key: str, account_id: str = ADMIN_ACCOUNT_ID) -> None:
         now = datetime.now(timezone.utc).isoformat()
         with self._connect() as conn:
             conn.execute(
@@ -76,7 +76,7 @@ class OpenVikingUserKeyStore:
                     user_key = excluded.user_key,
                     updated_at = excluded.updated_at
                 """,
-                (user_id, ADMIN_ACCOUNT_ID, user_key, now, now),
+                (user_id, account_id, user_key, now, now),
             )
 
     def user_key_matches(self, user_id: str, user_key: str) -> bool: