v2.15.0

Added

• Added native rmcp-mux Unix-socket connections for explicitly sharing external MCP server processes across Pi sessions. Thanks j0e1 (@pWoLiAn) for issue #76.
• Added connection-time command resolution for HTTP bearer tokens and headers, OAuth client secrets, and stdio environment values, with !! escaping and fail-closed execution. Thanks @estrizhok for issue #221.

Fixed

• Treated null optional server URLs as absent and cleaned unpublished runtimes after initialization failures, preventing not_initialized sessions with surviving MCP children. Thanks @autopeasant for the diagnosis in issue #222.
• Registered env-selected direct MCP tools before child agent_start when their metadata cache must be populated first. Thanks @peedrr for the original report in pi-subagents issue #638 and issue #219.