The default Serilog config set rollingInterval only, so Serilog's own defaults
applied: no size-based roll and a 1 GB ceiling after which the sink silently
stops writing. A busy install (many accounts scanned several times an hour)
reaches tens of MB in a month, past the point where the log can be attached to
a bug report.
Add fileSizeLimitBytes, rollOnFileSizeLimit and retainedFileCountLimit to the
default File sink, and fill in whichever of the three an existing Settings.json
is missing so installs that already have a Serilog section benefit too. Only
absent keys are written, so a hand-tuned config is left alone.
Co-authored-by: rmcrackan <rmcrackan@gmail.com>
