feat: improve test coverage and fix compatibility issues

[wasabeef]

🎯 Summary

This PR introduces a comprehensive Flutter Web demo site showcasing all 36 hooks from the flutter_use basic package, along with
various code quality improvements and CI/CD enhancements.

✨ Key Features

1. Complete Interactive Demo Site 🌐

• Added a new Flutter Web demo application with interactive examples for all 36 hooks
• Organized hooks into logical categories:
  • 🎯 State Management (9 hooks)
  • 🎭 Effects & Lifecycle (7 hooks)
  • ⚡ Performance & Optimization (6 hooks)
  • 📜 Scroll & Navigation (2 hooks)
  • 🛠️ Utility & Integration (12 hooks)
• Each demo includes:
  • Live interactive examples
  • Code snippets with syntax highlighting
  • Clear explanations of hook behavior
  • Visual feedback for state changes

2. GitHub Pages Deployment 🚀

• Configured automatic deployment to GitHub Pages
• Added GitHub Actions workflow (deploy-demo.yml)
• Integrated with melos for consistent builds
• Demo will be accessible at https://wasabeef.github.io/flutter_use/

3. Code Quality Improvements 🛠️

• Fixed all static analysis warnings and errors
• Replaced deprecated withOpacity() with withValues(alpha:) across 26 files
• Removed unused variables and imports
• Added proper control flow braces for better code style
• Ensured all demos match the actual hook APIs

4. CI/CD Enhancements 🔄

• Added test-coverage script to melos configuration
• Removed codecov upload steps for simpler CI
• Integrated asdf tool version management (.tool-versions)
• Updated melos configuration to include demo package

📝 Changes

New Files

• demo/ - Complete Flutter Web demo application
• .github/workflows/deploy-demo.yml - GitHub Pages deployment workflow
• .tool-versions - Tool version management for Flutter and Dart

Modified Files

• melos.yaml - Added demo package and new scripts (demo-build, demo-run, test-coverage)
• .github/workflows/ci.yaml - Removed codecov integration
• packages/basic/lib/src/use_click_away.dart - Fixed control body styling
• Various demo files - Fixed withOpacity deprecation warnings

Deleted Files

• .github/workflows/coverage.yaml - Removed dedicated coverage workflow
• packages/basic/example/ - Replaced by centralized demo app

🧪 Testing

• All hooks have been tested with interactive demos
• Static analysis passes with no issues
• Demo app runs successfully on Flutter Web
• CI workflows updated and functional

🚀 Deployment

Once merged, the demo site will automatically deploy to GitHub Pages and be accessible at:
https://wasabeef.github.io/flutter_use/

📋 Checklist

• All 36 basic package hooks have interactive demos
• Static analysis passes (melos analyze)
• Demo app builds and runs successfully
• GitHub Actions workflow configured
• Tool versions specified in .tool-versions
• All deprecated APIs updated
• Unused code removed