v0.9.8.1

### v0.9.8.1 - Caching, context optimization, error handling...
- improved caching for anthropic models
- improved context window optimimization
- fixed retry on critical error counter
- load up to 5 skills at a time
- default chat model is now Sonnet 4.6


### v0.9.8 - Skills, UI Redesign & Git projects
[Release video](https://youtu.be/NV7s78yn6DY)

- Skills
    - Skills System replacing the legacy Instruments with a new `SKILL.md` standard for structured, portable agent capabilities.
    - Built-in skills, and UI support for importing and listing skills
- Real-time WebSocket infrastructure replacing the polling-based approach for UI state synchronization
- UI Redesign
    - Process groups to visually group agent actions with expand/collapse support
    - Timestamps, steps count and execution time with tool-specific badges
    - Step detail modals with key-value and raw JSON display
    - Collapsible responses with show more/less and copy buttons on code blocks and tables
    - Message queue system allowing users to queue messages while the agent is still processing
    - In-browser file editor for viewing and editing files without leaving the UI
    - Welcome screen redesign with info and warning banners for connection security, missing API keys, and system resources
    - Scheduler redesign with standalone modal, separate task list, detail and editor components, and project support
    - Smooth response rendering and scroll stabilization across chat, terminals, and image viewer
    - Chat width setting and reworked preferences panel
    - Image viewer improvements with scroll support and expanded viewer
    - Redesigned sidebar with reusable dropdown component and streamlined buttons
    - Inline button confirmations for critical actions
    - Improved login design and new logout button
    - File browser enhanced with rename and file actions dropdown
- Git projects
    - Git-based projects with clone authentication for public and private repositories
- Four new LLM providers: CometAPI, Z.AI, Moonshot AI, and AWS Bedrock
- Microsoft Dev Tunnels integration for secure remote access
- User data migration to `/usr` directory for cleaner separation of user and system files
- Subagents system with configurable agent profiles for different roles
- Memory operations offloaded to deferred tasks for better performance
- Environment variables can now configure settings via `A0_SET_*` prefix in `.env`
- Automatic migration with overwrite support for `.env`, scheduler, knowledge, and legacy directories
- Projects support extended to MCP, A2A, and external API
- Workdir outside project support for more flexible file organization
- Agent number tracking in backend and responses for multi-agent identification
- Many bug fixes and stability improvements across the UI, MCP tools, scheduler, uploads, and WebSocket handling