Fix CodeQL comments from PR 305

[suguanYang]

Summary

• Resolve the CodeQL review comments on #305 (main → staging) in worker debug scripts.
• Drop unused tracker assignments, a redundant comparison, a duplicate re import, and import * namespace pollution.
• Replace empty except cleanup paths with unlink(missing_ok=True) / warning logs, and mark intentional re-exports in __all__.

Test plan

• Confirm CodeQL no longer flags the previous comments on debug_parse.py, debug_retrieval.py, and scripts/page_memory/*
• uv run --all-packages --group lint ruff check apps/worker/scripts/debug_parse.py apps/worker/scripts/debug_retrieval.py apps/worker/scripts/page_memory
• git diff --check

Made with Cursor