fix(tests): reduce TTL durations to improve test reliability

- Adjusted TTL durations and sleep intervals across memory and cache tests for consistent expiration behavior.
- Prevented test flakiness caused by timing discrepancies in token expiration and cache cleanup.

backend/tests/unit/services/memory/working/test_storage.py

@@ -78,13 +78,13 @@ class TestInMemoryStorageTTL:
     @pytest.mark.asyncio
     async def test_ttl_expiration(self, storage: InMemoryStorage) -> None:
         """Test that expired keys return None."""
-        await storage.set("key1", "value1", ttl_seconds=1)
+        await storage.set("key1", "value1", ttl_seconds=0.1)
 
         # Key exists initially
         assert await storage.get("key1") == "value1"
 
         # Wait for expiration
-        await asyncio.sleep(1.1)
+        await asyncio.sleep(0.15)
 
         # Key should be expired
         assert await storage.get("key1") is None
@@ -93,10 +93,10 @@ class TestInMemoryStorageTTL:
     @pytest.mark.asyncio
     async def test_remove_ttl_on_update(self, storage: InMemoryStorage) -> None:
         """Test that updating without TTL removes expiration."""
-        await storage.set("key1", "value1", ttl_seconds=1)
+        await storage.set("key1", "value1", ttl_seconds=0.1)
         await storage.set("key1", "value2")  # No TTL
 
-        await asyncio.sleep(1.1)
+        await asyncio.sleep(0.15)
 
         # Key should still exist (TTL removed)
         assert await storage.get("key1") == "value2"
@@ -180,10 +180,10 @@ class TestInMemoryStorageCapacity:
         """Test that expired keys are cleaned up for capacity."""
         storage = InMemoryStorage(max_keys=2)
 
-        await storage.set("key1", "value1", ttl_seconds=1)
+        await storage.set("key1", "value1", ttl_seconds=0.1)
         await storage.set("key2", "value2")
 
-        await asyncio.sleep(1.1)
+        await asyncio.sleep(0.15)
 
         # Should succeed because key1 is expired and will be cleaned
         await storage.set("key3", "value3")