fix(chat/sdk): address PR #12103 review comments

- Remove duplicate security check in _cleanup_sdk_tool_results (copy-paste)
- Don't delete transcript on transient errors — only the current
  turn failed, the transcript is still valid for future resume
- Add post-construction realpath check in write_transcript_to_tempfile
  to satisfy CodeQL taint analysis

autogpt_platform/backend/backend/api/features/chat/sdk/service.py

@@ -46,7 +46,6 @@ from .tool_adapter import (
     set_execution_context,
 )
 from .transcript import (
-    delete_transcript,
     download_transcript,
     read_transcript_file,
     upload_transcript,
@@ -278,13 +277,8 @@ def _cleanup_sdk_tool_results(cwd: str) -> None:
     """
     import shutil
 
-    # Security check 1: Validate cwd is under the expected prefix
+    # Validate cwd is under the expected prefix
     normalized = os.path.normpath(cwd)
-    if not normalized.startswith(_SDK_CWD_PREFIX):
-        logger.warning(f"[SDK] Rejecting cleanup for invalid path: {cwd}")
-        return
-
-    # Security check 2: Verify path stayed within workspace after normalization
     if not normalized.startswith(_SDK_CWD_PREFIX):
         logger.warning(f"[SDK] Rejecting cleanup for path outside workspace: {cwd}")
         return
@@ -718,11 +712,6 @@ async def stream_chat_completion_sdk(
 
     except Exception as e:
         logger.error(f"[SDK] Error: {e}", exc_info=True)
-        if use_resume and user_id:
-            logger.warning("[SDK] Deleting transcript after resume failure")
-            task = asyncio.create_task(delete_transcript(user_id, session_id))
-            _background_tasks.add(task)
-            task.add_done_callback(_background_tasks.discard)
         try:
             await upsert_chat_session(session)
         except Exception as save_err:

autogpt_platform/backend/backend/api/features/chat/sdk/transcript.py

@@ -180,7 +180,12 @@ def write_transcript_to_tempfile(
     try:
         os.makedirs(real_cwd, exist_ok=True)
         safe_id = _sanitize_id(session_id, max_len=8)
-        jsonl_path = os.path.join(real_cwd, f"transcript-{safe_id}.jsonl")
+        jsonl_path = os.path.realpath(
+            os.path.join(real_cwd, f"transcript-{safe_id}.jsonl")
+        )
+        if not jsonl_path.startswith(real_cwd):
+            logger.warning(f"[Transcript] Path escaped cwd: {jsonl_path}")
+            return None
 
         with open(jsonl_path, "w") as f:
             f.write(transcript_content)