Best-effort run metadata uploads bounded to 15 seconds

Best-effort run metadata uploads are now time-budgeted to 15 seconds in both the foreground (CI) and the hidden background analytics-uploader, so commands such as tuist install finish promptly even when the configured server is slow or unreachable. The retry provider also runs in the caller task now, so cancellation from the deadline actually interrupts in-flight retries and retry sleeps rather than logging late. Required (build/test) report uploads are unaffected and keep their previous foreground behavior.