(ui) Add dashboard-linked run and snapshot lists

Add staff-only list pages for backup runs and snapshots with practical
filters, then wire the dashboard summary cards and latest-runs panel to
those overviews.

This gives the dashboard real drill-down paths for run and snapshot counts
instead of leaving the data only partially visible on the first screen.

Refs #23

src/pobsync_backend/views.py

@@ -145,6 +145,64 @@ def logs(request):
     return render(request, "pobsync_backend/logs.html", context)
 
 
+@staff_member_required
+def runs_list(request):
+    status = request.GET.get("status", "").strip()
+    run_type = request.GET.get("type", "").strip()
+    host = request.GET.get("host", "").strip()
+    review = request.GET.get("review", "").strip()
+    runs = BackupRun.objects.select_related("host", "snapshot").order_by("-created_at", "-id")
+    if status:
+        runs = runs.filter(status=status)
+    if run_type:
+        runs = runs.filter(run_type=run_type)
+    if host:
+        runs = runs.filter(host__host=host)
+    if review == "needed":
+        runs = runs.filter(status__in=[BackupRun.Status.FAILED, BackupRun.Status.WARNING], reviewed_at__isnull=True)
+    elif review == "reviewed":
+        runs = runs.filter(reviewed_at__isnull=False)
+
+    context = {
+        "runs": runs[:200],
+        "total_count": runs.count(),
+        "hosts": HostConfig.objects.order_by("host"),
+        "statuses": BackupRun.Status.choices,
+        "run_types": BackupRun.RunType.choices,
+        "selected_status": status,
+        "selected_type": run_type,
+        "selected_host": host,
+        "selected_review": review,
+    }
+    return render(request, "pobsync_backend/runs_list.html", context)
+
+
+@staff_member_required
+def snapshots_list(request):
+    kind = request.GET.get("kind", "").strip()
+    status = request.GET.get("status", "").strip()
+    host = request.GET.get("host", "").strip()
+    snapshots = SnapshotRecord.objects.select_related("host", "base").order_by("-started_at", "-discovered_at", "-id")
+    if kind:
+        snapshots = snapshots.filter(kind=kind)
+    if status:
+        snapshots = snapshots.filter(status=status)
+    if host:
+        snapshots = snapshots.filter(host__host=host)
+
+    context = {
+        "snapshots": snapshots[:200],
+        "total_count": snapshots.count(),
+        "hosts": HostConfig.objects.order_by("host"),
+        "kinds": SnapshotRecord.Kind.choices,
+        "statuses": SnapshotRecord.objects.exclude(status="").order_by("status").values_list("status", flat=True).distinct(),
+        "selected_kind": kind,
+        "selected_status": status,
+        "selected_host": host,
+    }
+    return render(request, "pobsync_backend/snapshots_list.html", context)
+
+
 @staff_member_required
 def purged_snapshots(request):
     host = request.GET.get("host", "").strip()