[Tech Improvement] Migrating to `auto_route` for routing

[fres-sudo]

📝 Improvement Description

Migrate from the default Flutter routing system to auto_route package for better type-safe navigation, code generation, and improved developer experience.

🛑 Problem Statement

The current default routing system lacks type safety, requires manual route configuration, and makes navigation code verbose and error-prone. String-based route names are difficult to maintain and refactor, leading to runtime errors and poor developer experience.

💡 Proposed Solution

1. Add auto_route dependency to pubspec.yaml
2. Create AppRouter class with @AutoRouterConfig annotation
3. Define routes using @RoutePage annotations on page widgets
4. Generate routing code using build_runner
5. Replace MaterialApp with MaterialApp.router
6. Update all Navigator.pushNamed calls to use context.router.push()
7. Implement nested routing where applicable
8. Add route guards for authentication if needed

🌿 Benefits

• Type-safe routing with compile-time error checking
• Code generation reduces boilerplate and human errors
• Better IDE support with auto-completion for routes
• Easier refactoring and maintenance
• Support for nested routing and complex navigation patterns
• Built-in route guards and middleware support
• Improved developer experience and productivity
• Better testability of navigation logic

🧱 Impact Area

• Backend
• Frontend
• Infrastructure
• DevOps
• Other

✍️ Additional Context

Related packages to consider:

• auto_route
• auto_route_generator
• build_runner

Build Runner Introduction Consequences:
🔄 Development workflow: Requires running dart run build_runner build after route changes
🏗️ CI/CD impact: Build pipelines must include code generation step before compilation
📁 Git considerations: Generated files (*.gr.dart) shouldn't be committed to version control
👥 Team coordination: All developers must run build_runner after pulling route changes
⏱️ Build time: Initial setup and route changes will slightly increase build duration
🐛 Debugging: Generated code may complicate stack traces and debugging
📦 Dependency management: Additional dev dependencies increase project complexity
💻 IDE integration: Some IDEs may require restart after code generation

Migration checklist:

• Update pubspec.yaml dependencies
• Create router configuration
• Annotate existing pages
• Generate routing code
• Update main.dart
• Replace all navigation calls
• Test all navigation flows
• Update CI/CD pipeline for build_runner
• Update development documentation
• Configure IDE/editor for generated files

📜 Code of Conduct

• ✅ I agree to the Code of Conduct