docs: Add comprehensive release checklist

📋 Release Checklist v2.0.0:
- Complete production readiness verification
- All testing, bug fixes, and features documented
- Distribution files and documentation confirmed
- Technical quality and version management verified

✅ BlockMaster v2.0.0 is confirmed production-ready
with zero critical issues and comprehensive testing completed.

Author: bythebug

RELEASE_CHECKLIST.md

@@ -0,0 +1,82 @@
+# BlockMaster v2.0.0 - Release Checklist
+
+## ✅ Production Readiness
+
+### 🧪 Testing
+- [x] **Comprehensive End-to-End Testing**: All components tested and verified
+- [x] **No Critical Issues**: Production-ready status confirmed
+- [x] **All Dependencies Verified**: All required packages available
+- [x] **File Structure Validated**: All files present and properly configured
+- [x] **Syntax Validation**: All Python files have valid syntax
+- [x] **Installer Scripts Tested**: All installation scripts working correctly
+
+### 🐛 Bug Fixes
+- [x] **Website Removal Issue**: Fixed - websites now unblock immediately
+- [x] **Hosts File Cleaning**: Enhanced - proper removal of markers and entries
+- [x] **pfctl Rules Management**: Improved - safer firewall handling
+- [x] **URL Processing**: Smart handling of complex URLs with subdomains/paths
+- [x] **TkinterSudoHelper**: Fixed initialization requiring parent_window parameter
+- [x] **DNS Cache Flushing**: Enhanced with browser-specific cache clearing
+
+### 🚀 New Features
+- [x] **Professional DMG Installer**: Single-file download and installation
+- [x] **Enhanced DNS Cache Flushing**: System + browser cache clearing
+- [x] **Simplified Launcher**: Clean, single-button interface
+- [x] **Professional Branding**: BlockMaster with author information
+- [x] **Production Ready**: Comprehensive testing and validation
+
+### 📦 Distribution Files
+- [x] **DMG Installer**: `BlockMaster-2.0.0.dmg` (140KB) created
+- [x] **Install Scripts**: `install.sh`, `download.sh` working
+- [x] **Documentation**: README.md, INSTALL.md, BUILD_DMG.md updated
+- [x] **Source Code**: All files properly organized in `src/` directory
+- [x] **Dependencies**: `requirements.txt` with all needed packages
+
+### 📚 Documentation
+- [x] **README.md**: Updated with new features and fixes
+- [x] **INSTALL.md**: Comprehensive installation guide
+- [x] **BUILD_DMG.md**: DMG creation guide for developers
+- [x] **LICENSE**: MIT license included
+- [x] **CONTRIBUTING.md**: Contribution guidelines
+- [x] **QUICK_START.md**: Quick start guide
+
+### 🔧 Technical Quality
+- [x] **Code Quality**: All Python files compile without errors
+- [x] **Error Handling**: Comprehensive error handling throughout
+- [x] **Safety Measures**: Automatic backups and rollback capabilities
+- [x] **Permission Handling**: Proper sudo integration with GUI prompts
+- [x] **System Safety**: No destructive operations without safeguards
+
+### 🎯 Version Management
+- [x] **Version Numbers**: Consistent v2.0.0 across all files
+- [x] **Git History**: Clean commit history with descriptive messages
+- [x] **Release Notes**: Documented in README.md
+- [x] **Author Information**: Proper attribution in all source files
+
+## 🚀 Ready for Release!
+
+**BlockMaster v2.0.0 is production-ready with:**
+- ✅ Zero critical issues
+- ✅ Comprehensive testing completed
+- ✅ Professional DMG installer
+- ✅ Updated documentation
+- ✅ All bug fixes applied
+- ✅ Clean codebase
+- ✅ Proper versioning
+
+**Distribution Ready:**
+- DMG file: `BlockMaster-2.0.0.dmg`
+- Installation methods: DMG, script, manual
+- Documentation: Complete and up-to-date
+- Testing: Thoroughly validated
+
+**Next Steps:**
+1. Upload DMG to GitHub Releases
+2. Update download links in documentation
+3. Announce release to users
+4. Monitor for any user feedback
+
+---
+**Release Date**: October 9, 2024  
+**Version**: 2.0.0  
+**Status**: ✅ PRODUCTION READY