The end /v3/computes/{compute_id} expects the compute_id to be a
valid UUID. Previously the MCP tool defaulted to the string 'local',
which caused a ValueError in the database layer. Now compute_id is
required and callers must use compute_list first to resolve names to UUIDs.
- Move node file operations (list_files, delete_file) from Gns3Connector to Node class
- Add link capture/reset operations (reset, start_capture, stop_capture) to Link class
- Convert all MCP handlers to use conn.http_call() directly instead of
Gns3Connector/Node/Link abstraction methods
- Register 4 new MCP tools: reset_link, start_capture, stop_capture,
download_capture_file