fix(backend): robust PORT handling and bind to 0.0.0.0 for Render

fix error

style(ui): dark select dropdowns for better readability

feat: language selection (en/fa) in frontend; backend prompts respect language

fix(ui): remove fullscreen, enlarge output panel, enable typography via CSS plugin

feat(ui): markdown-it + highlight.js, typography plugin, redesigned output (top panel, fullscreen), modern layout

chore: add root .gitignore

feat(frontend): scaffold Vite React TS app with Tailwind and minimal UI calling backend

Create README.md

chore: initial scaffold (backend TS+Express, OpenRouter integration), README, gitignore