* fix(beszel): harden cache layer and prevent blank widgets
- Add debug logging across Beszel integration, request handler, and tRPC
router (auth, fetch, SSE, per-procedure entry/exit) gated behind
LOG_LEVEL=debug
- cached-request-handler: retry with backoff, isValid predicate to skip
caching invalid data, in-flight dedup (single-flight per channel) to
avoid thundering herd after cache invalidation
- redis channel: set-then-publish so storage is always consistent even
when pubsub publish fails
- Beszel handlers: opt into fallbackToStaleOnError and retry so brief
upstream hiccups don't throw away good cached data
- beszel-system-stats: add refetchInterval matching each time period's
cache TTL so historical charts refresh in the background
- tRPC router: switch Promise.all -> Promise.allSettled for getSystems
and getAlerts; getSystemStats returns an error object instead of
throwing. Each result carries an optional error field so one failed
integration no longer nukes the whole widget
- Widgets: add explicit isPending loader, empty state for grid and
stats, and a shared per-integration error indicator (tooltip with
failed integration names). Alerts and table now only show their
empty state after loading completes
- Translation: add empty.noSystems key to beszelSystemGrid and
beszelSystemStats
Addresses #6030
* style: auto-fix lint and format
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Co-authored-by: ajnart <ajnart@users.noreply.github.com>