chore: Clean up orphaned files and update .gitignore

- Delete orphaned files: temp_compare.py, run_cleanup.py
- Delete stale cache files from archive/temp_outputs/
- Update .gitignore with .coverage.*, .obsidian/ entries

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -22,6 +22,7 @@ wheels/
 MANIFEST
 .pytest_cache/
 .coverage
+.coverage.*
 htmlcov/
 *.cover
 .hypothesis/
@@ -35,6 +36,7 @@ env/
 # IDEs
 .vscode/
 .idea/
+.obsidian/
 *.swp
 *.swo
 *~