Drop the Supabase backend and call the AI provider directly from the
browser. The endpoint URL, API key, and model name are stored in
localStorage and used for direct /chat/completions requests.
- src/lib/llm.ts: config persistence, direct fetch, JSON extraction,
shape validation, connection test
- src/lib/prompts.ts: full + partial-regeneration system prompts and
user-message builder
- src/lib/{api,supabase}.ts removed
- supabase/ directory removed
- @supabase/supabase-js dropped from package.json
- README updated to describe the standalone architecture and CORS caveats
- .gitignore: drop Supabase entries, exclude *.tsbuildinfo