Alexey Dolotov
d6c99c7209
doctor: use WaitGroup.Go and recover panics in DC probes
Address review feedback on #485:
- switch to sync.WaitGroup.Go (Go 1.25+) for the per-DC goroutine
- recover panics inside the goroutine and record them as that DC's
error, so a single panicking probe no longer crashes the whole
doctor run and the remaining DCs still report their results