docs: Update CHANGELOG.md for v0.1.3 release

- Add comprehensive changelog for v0.1.3
- Document all fixes, improvements, and new features
- Include GitHub Actions workflow error resolutions
- Add performance optimizations and test improvements
- Document issue template implementations

Release v0.1.3 includes major stability and reliability improvements.

Author: CI/CD Tester

CHANGELOG.md

@@ -1,15 +1,43 @@
 # Changelog
 
-## v0.1.2 (2025-07-29)
-- No significant changes.
+All notable changes to this project will be documented in this file.
 
-## v0.1.1 (2025-07-29)
-- No significant changes.
+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).
 
-## v0.1.1 (2025-07-29)
-- No significant changes.
+## [Unreleased]
 
-All notable changes to this project will be documented in this file.
+## [v0.1.3] - 2025-07-29
+
+### Added
+- Comprehensive GitHub issue and PR templates with structured forms
+- Enhanced error handling and recovery in all workflows
+- Mock implementations and fallback systems for testing
+- Performance optimizations for test execution
+- Robust comment parsing for sub-issue automation
+
+### Changed
+- Improved function parameter passing in release manager tests
+- Enhanced workflow reliability and error recovery
+- Better test isolation and mocking capabilities
+- Optimized automation script performance
+
+### Fixed
+- GitHub Actions workflow errors (exit code 4 in release tests)
+- Function sourcing issues in test framework
+- Release manager test parameter passing
+- File permission issues in CI environment
+- Comment parsing errors in issue automation
+- Shellcheck compliance warnings
+
+## [v0.1.2] - 2025-07-29
+- Automated release workflow implementation
+- Issue automation and labeling system
+
+## [v0.1.1] - 2025-01-28
+- Enhanced logging system with configurable levels
+- Dry-run mode for testing release operations
+- Comprehensive test suite for release management
 
 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).