Diagnose silent link-open failures from the app debug log first

When a terminal app answers a Cmd-clicked file link with only system beeps, check its debug log before you read code. Tally the open-start and open-failed events and split them by relative versus absolute link paths. Here every relative path failed and every absolute path opened, which pointed straight at link resolution against the remote shell's cwd. The beep and the file type were red herrings. Also make sure the failure path logs a reason; a bare 'failed' event cost a round of guessing.