Remove unused imports and dead code from checksum module

backend/app/checksum.py

@@ -18,12 +18,8 @@ import logging
 import re
 import base64
 from typing import (
-    Iterator,
     Generator,
     Optional,
-    Tuple,
-    Union,
-    BinaryIO,
     Any,
     Callable,
 )
@@ -479,35 +475,3 @@ class VerifyingStreamWrapper:
     def get_actual_hash(self) -> Optional[str]:
         """Get the actual computed hash (only available after iteration)."""
         return self._hashing_wrapper.get_hash_if_complete()
-
-
-def create_verifying_generator(
-    stream: Any,
-    expected_hash: str,
-    artifact_id: Optional[str] = None,
-    s3_key: Optional[str] = None,
-    chunk_size: int = DEFAULT_CHUNK_SIZE,
-) -> Tuple[Generator[bytes, None, None], "VerifyingStreamWrapper"]:
-    """
-    Create a verifying generator and its wrapper for manual verification.
-
-    This is useful when you need to iterate and later verify manually.
-
-    Args:
-        stream: Source stream
-        expected_hash: Expected SHA256 hash
-        artifact_id: Optional artifact ID
-        s3_key: Optional S3 key
-        chunk_size: Chunk size for reading
-
-    Returns:
-        Tuple of (generator, wrapper) where wrapper has verify() method
-    """
-    wrapper = VerifyingStreamWrapper(
-        stream=stream,
-        expected_hash=expected_hash,
-        artifact_id=artifact_id,
-        s3_key=s3_key,
-        chunk_size=chunk_size,
-    )
-    return iter(wrapper), wrapper