Stop lost responses duplicating your runs

A run upload whose response never made it back to the station was re-sent and stored a second time, so one test appeared twice on the dashboard.

• Added an idempotency reference that the CLI mints and saves before its first upload attempt, so every retry of the same run returns the run already created instead of storing another one.
• Removed a redundant retry loop inside the CLI upload queue, which had turned a single queued attempt into up to four uploads.
• Extended the reference to the Python, C#, Rust, C++ and MATLAB clients, and to stations already in the field, which pick it up on upgrade with no re-login.