chore: add CHANGELOG.md to document project updates and version history

Author: hulxv

CHANGELOG.md

@@ -0,0 +1,47 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [1.0.2] - 2025-10-17
+
+### Changed
+- Updated `mio-rs` to version `1.1.0` which includes the fix for macOS thread safety issues
+
+### Fixed
+- Resolved macOS thread safety issues with `mio::Event` in worker threads (initially fixed with custom Event wrapper #70, then properly resolved by updating mio-rs after upstream fix #72)
+
+### Development
+- Enhanced CI/CD with cross-platform testing workflows
+- Fixed clippy linting issues
+- Added unstable feature testing with nightly Rust channel
+- Improved CI workflow to avoid using `unstable` features in stable & beta channels
+- Added TCP tests and disabled UDS tests on Windows for better cross-platform support
+- Fixed documentation errors
+
+## [1.0.1] - 2025-9-16
+
+### Documentation
+- Fixed documentation errors throughout the codebase
+- Enhanced README.md with better explanations and examples
+
+### Development
+- Bumped version for documentation fixes
+
+## [1.0.0] - 2025-9-15
+
+### Added
+- Complete event loop implementation with reactor pattern
+- Thread pool for efficient task execution
+- Object pool for memory management optimization
+- Polling abstraction layer with `PollHandle`
+- Error handling module with custom error types
+- Event loop registration and deregistration capabilities
+- Multiple channel types (MPMC/MPSC) for inter-thread communication
+
+### Examples
+- **Echo Server**: Complete TCP echo server implementation
+- **HTTP Server**: Basic HTTP server example
+- **File Watcher**: File system monitoring example  
+- **JSON-RPC Server**: JSON-RPC protocol server implementation