fix(rclone): honor rcd restart tolerance duration

[javi11]

The rcd health check now waits the configured restart tolerance before restarting. A 90-second tolerance requires four failed probes at 0, 30, 60, and 90 seconds; previously three probes triggered a restart after only 60 seconds. Duration rounding remains overflow-safe, and unset or invalid settings use the corrected 90-second fallback.

Closes #967.

Validation:

• Regression tests cover exact and fractional interval boundaries, invalid/default values, and maximum durations.
• A fake RC HTTP server exercises failures, successful-probe resets, and restart resets.
• go test ./..., go test -race ./pkg/rclonecli -count=1, and go vet ./pkg/rclonecli passed.

Timing remains rounded up to the 30-second monitoring interval. The pinned golangci-lint cannot decode Go 1.27 export data; lint validation remains unavailable locally.