Fix .gitignore __pycache__ typo and reorganize reports

- Fix critical typo: ___pycache__ → __pycache__/ (was using 3 underscores)
- Add .ruff_cache/ to ignored directories
- Move reports/ directory into data/ for better organization
- Remove obsolete claude-usage.md

The __pycache__ typo caused Python cache directories to not be ignored,
resulting in bytecode files being tracked in the repository.

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

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

Author: marcarl

.gitignore

@@ -1,5 +1,5 @@
 .env
-___pycache__
+__pycache__/
 *.pyc
 *.egg-info/
 .DS_Store
@@ -11,6 +11,10 @@ ___pycache__
 .coverage
 htmlcov/
 .pytest_cache/
+.ruff_cache/
+
+# Ignore input files
+sfs_docs
 
 # Ignore output files
 logs/