v0.21.3: MCP OAuth, system certificates, fuzzy search, and session management improvements

New features and enhancements

- MCP OAuth support: Added OAuth authentication support for Model Context Protocol in TUI for secure server connections
- System certificates support: Added support for loading system certificates on Windows and macOS, with additional Windows system certificates support
- Fuzzy search implementation: New fuzzy search for improved CLI command and option discovery
- Rewind fork workflow: Added ability to rewind and fork from previous points in conversation sessions
- Bug report enhancements: Added version, OS, and shell information to bug reports for better troubleshooting
- Live updates for subagent tool: Added real-time progress updates when using the Task tool
- Enhanced custom droid prompts: Improved prompts to encourage more proactive usage of custom droids
- Droid Shield optional setting: Made Droid Shield an optional configurable setting with toggle support

Bug fixes and stability

- Added session_id to stream-json output format for better tracking and debugging
- Enhanced authentication flow for smoother onboarding
- Streamlined first-run experience by removing redundant onboarding steps
- Fixed OAuth callback server port collision issues that prevented authentication
- Fixed certificate loading timing issues causing TLS errors
- Improved error metadata logging for better debugging
- Fixed terminal setup issues across different shell environments
- Better error messages when ripgrep (rg) isn't available in PATH
- Improved handling of corrupted unicode normalization in file paths
- Fixed impact level default value handling