Refactor message optimization: extract helpers, consolidate diff extraction, add lint hooks

[hiroshinishio]

Summary

• Refactored monolithic remove_outdated_file_edit_attempts.py (338 lines) into focused single-responsibility modules: detect_outdated_tool_ids.py, track_tool_use.py, extract_diff_result_file_path.py, remove_tool_pairs.py, remove_outdated_user_messages.py, remove_outdated_messages.py
• Consolidated duplicate extract_diff_file_path + extract_success_diff_file_path into one function with a DIFF_MARKERS table
• Added shared file_tracking.py for FilePosition, FileReadEntry, FILE_EDIT_TOOLS types
• Used proper Anthropic SDK types (ToolResultBlockParam, ToolUseBlockParam) with pyright discriminated union narrowing instead of cast or bare dict
• Added 3 new pre-commit lint hooks: check_cast_usage.sh, check_private_functions.sh, check_partial_assertions.sh
• 43 new tests across 7 test files covering every extracted module

Social Media Post (GitAuto)

Refactored message optimization into single-responsibility modules

• Split 338-line monolith into 6 focused files with proper SDK types
• Consolidated duplicate diff extraction functions into one with a marker table
• Added pre-commit hooks blocking cast(), private functions, and partial assertions

Social Media Post (Wes)

Spent a day splitting one giant function into six small ones. The function worked fine. But every time I touched it, I had to re-read 300 lines to find the part I needed. Now each piece is obvious. Boring refactor, faster future changes.