feat: add fix_format.py to automatically correct paragraph spacing violations

fix: add explicit no-blank-line rule for paragraphs in writing-guide

research v2: add Jina Reader for clean content extraction, upgrade source tiers, fix Tavily API key resolution

feat: add Step 3.2 research search — sources graded, materials package generated before writing

fix: replace venv paths with python3, add env var config loader, fix datetime warnings

Initial commit