initial: Backend Auth Module + Design System + Complete Documentation

- Setup NestJS with TypeScript, ConfigModule, JWT authentication
- Implemented Auth Module with signup, login, logout endpoints
- Created DTOs with validation (SignupDto, LoginDto)
- JWT Strategy with Passport integration for token validation
- JwtAuthGuard for route protection with Bearer tokens
- CurrentUser decorator for dependency injection
- Supabase integration for user management and auth
- Complete API documentation (API.md) with all endpoints
- Design System for Web (Next.js + Tailwind) and Mobile (Flutter)
- Comprehensive project documentation and roadmap
- Environment configuration with Joi schema validation
- Ready for Tasks Module and RLS implementation

.gitignore

@@ -0,0 +1,51 @@
+# Environment variables
+.env
+.env.local
+.env.*.local
+
+# Dependencies
+node_modules/
+.dart_tool/
+.flutter/
+
+# Build outputs
+dist/
+build/
+.next/
+out/
+*.apk
+*.app
+*.ipa
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+.DS_Store
+
+# Logs
+logs/
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Coverage
+coverage/
+.nyc_output/
+
+# OS
+Thumbs.db
+.DS_Store
+
+# Flutter/Dart specific
+.pub
+.dart_tool
+.fvm
+.flutter
+
+# Test
+test/**/*.js
+test/**/*.js.map