fix: Add .delta suffix fallback for delete_object()

- delete_object() now tries with .delta suffix if file not found
- Matches the same fallback logic as download/get_object
- Fixes deletion of files uploaded as .delta when user provides original name
- Add test for delta suffix fallback in deletion

This fixes the critical bug where delete_object(Key='file.zip') would fail
with NotFoundError when the actual file was stored as 'file.zip.delta'.

Now delete_object() works consistently with get_object():
- Try with key as provided
- If NotFoundError and no .delta suffix, try with .delta appended
- Raises NotFoundError only if both attempts fail

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

Co-Authored-By: Claude <noreply@anthropic.com>

src/deltaglider/client.py

@@ -8,6 +8,7 @@ from typing import Any
 
 from .adapters.storage_s3 import S3StorageAdapter
 from .core import DeltaService, DeltaSpace, ObjectKey
+from .core.errors import NotFoundError
 
 
 @dataclass
@@ -427,15 +428,23 @@ class DeltaGliderClient:
 
         Args:
             Bucket: S3 bucket name
-            Key: Object key
+            Key: Object key (can be with or without .delta suffix)
             **kwargs: Additional parameters
 
         Returns:
             Response dict with deletion details
         """
-        # Use core service's delta-aware delete
+        # Try to delete with the key as provided
         object_key = ObjectKey(bucket=Bucket, key=Key)
-        delete_result = self.service.delete(object_key)
+        try:
+            delete_result = self.service.delete(object_key)
+        except NotFoundError:
+            # Try with .delta suffix if not already present
+            if not Key.endswith(".delta"):
+                object_key = ObjectKey(bucket=Bucket, key=Key + ".delta")
+                delete_result = self.service.delete(object_key)
+            else:
+                raise
 
         response = {
             "DeleteMarker": False,