v0.3.0 of akashi_mcp

Model Context Protocol (MCP) tools for the Akashi agent framework: connect to an MCP server via dart_mcp and expose its tools as Akashi tools an agent can call. Changelog excerpt: - Upgrade to dart_mcp^0.5.1. connectStdionow spawns the server process and bridges its stdio via stdioChannel(the client no longer launches it internally); the process is killed on close(). Public API unchanged.