Add NoOpCache fallback

app/infrastructure/cache/noop_cache.py

@@ -0,0 +1,30 @@
+"""
+Infrastructure - No-Op Cache (Fallback when Redis unavailable)
+"""
+from typing import Any, Optional
+
+from app.domain.interfaces import ICache
+
+
+class NoOpCache(ICache):
+    """No-operation cache - does nothing (fallback)"""
+
+    async def get(self, key: str) -> Optional[Any]:
+        """Always return None (cache miss)"""
+        return None
+
+    async def set(self, key: str, value: Any, ttl: Optional[int] = None) -> bool:
+        """Do nothing, return True"""
+        return True
+
+    async def delete(self, key: str) -> bool:
+        """Do nothing, return True"""
+        return True
+
+    async def exists(self, key: str) -> bool:
+        """Always return False"""
+        return False
+
+    async def clear(self) -> bool:
+        """Do nothing, return True"""
+        return True