agent-platform release v4.104.0

Sessions list and message each other: kagent’s MCP server is registered with muster (giantswarm/agent-platform#705). With kagent’s controller route and muster on, the connectivity chart renders MCPServer kagent in the agent-platform tool group and an in-cluster HTTPRoute kagent-mcp. The route serves /kagent/mcp on the data plane’s plaintext listener, rewrites it to the controller’s /mcp on the kagent backend, and sits behind kagent-mcp-jwt, a twin of the kagent-controller-jwt policy (the CRD takes one kind of target per policy). muster forwards the session’s IdP token, so every call runs as the person who ran the turn. Agents on the agent-platform toolset preset get x_kagent_list_agent_instances (the person’s other ready sessions) x_kagent_invoke_agent_instance (a message to one of them, answered when its turn ends; kagent.controllerRoute.mcp.timeout, default 300 s, the CRD’s maximum) and the checkpoint and fork tools, and the Dev Portal’s MCP servers page lists kagent in the Agent Platform group. kagent.controllerRoute.mcp.enabled: false turns it off. make verify-kagent-route asserts the route, the CR, the twin policy, the off switches and the path guard.