SCOWL loader now sets frequency based on tier (10=1000 most common,
70=50 rare). New GET /frequency?word=X&lang=Y endpoint returns frequency
score for a word. Enables downstream consumers to identify rare/
sophisticated vocabulary from dictionary data rather than LLM guessing.
Also fix .gitignore matching cmd/server/ directory instead of just the
server binary.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>