This PR implements the requirements for #1301 by enabling graphical UI support for MCP components.

Changes:

• Backend: Implemented getAvailableTools in K8s runtime to probe for MCP apps.
• Schema: Extended AvailableToolSchema with mcpAppUrl.
• Frontend: Updated AgentToolsDisplay to handle App interaction and added McpAppPanel visual container for rendering third-party MCP App UIs.
• Compatibility: Supports auto-discovery of apps like Excalidraw-MCP.

/claim archestra-ai/archestra#1301