(bugfix) Show latest successful runs without requiring stats

Separate operational latest-run display from trend-stat collection so
successful backups without parsed stats still appear in dashboard host rows.

Keep trend summaries limited to runs with stats, but use all successful
real runs for the host latest-run indicator.

Render next scheduled run times with an explicit timezone label to avoid
ambiguity between UTC and local scheduler time.

src/pobsync_backend/views.py

@@ -58,6 +58,7 @@ def dashboard(request):
         "hosts": hosts,
         "global_config": global_config,
         "stats_summary": stats_summary,
+        "scheduler_timezone": timezone.get_current_timezone_name(),
         "latest_runs": BackupRun.objects.select_related("host", "snapshot").order_by("-created_at")[:10],
         "counts": {
             "global_configs": GlobalConfig.objects.count(),
@@ -271,6 +272,7 @@ def host_detail(request, host: str):
         "host": host_config,
         "schedule": schedule,
         "next_run_at": _next_run_for_schedule(schedule, host_config),
+        "scheduler_timezone": timezone.get_current_timezone_name(),
         "discovery": inspect_snapshot_discovery(host=host_config),
         "host_checks": host_checks,
         "host_check_summary": summarize_self_checks(host_checks),