Replace remote Tailwind CSS with a local minimal subset; refine .gitignore and dist structure.

- Added a minimal `tailwind.min.css` with utilities tailored to app needs (`app/web/dist/`).
- Updated `.gitignore` to include specific `dist/` paths while maintaining clean build artifacts.
- Added local `dist` files (`index.css`, `index.js`) for better control over UI styling and build outputs.

app/web/.gitignore

@@ -8,7 +8,6 @@ node_modules
 bun.lockb
 
 # Build directories
-dist
 build
 
 # Cache and logs