Add Redis scan_keys iterator API.

Provide a SCAN-based key iterator for Redis adapters so callers can enumerate large keyspaces without relying on blocking KEYS lookups.

Co-authored-by: Cursor <[email protected]>

python_repositories/interfaces/json_repository_interface.py

@@ -1,5 +1,6 @@
 """Definition of JsonRepositoryInterface abstract base class."""
 
+from collections.abc import Iterator
 from abc import ABC, abstractmethod
 
 
@@ -25,3 +26,13 @@ class JsonRepositoryInterface(ABC):
     def list_keys(self, pattern: str) -> list[str]:
         """List keys matching a glob pattern."""
         ...
+
+    def scan_keys(
+        self,
+        pattern: str,
+        *,
+        count: int | None = None,
+    ) -> Iterator[str]:
+        """Yield keys matching a glob pattern incrementally."""
+        del count
+        yield from self.list_keys(pattern)