(ui) Rework dashboard around operator priorities

Move required actions, upcoming scheduled work, and recent run activity to the
top of the dashboard so the first screen answers what needs attention next.
Keep summary metrics, trends, and host cards as supporting drill-down content.

Refs #27

src/pobsync_backend/views.py

@@ -4,7 +4,9 @@ import json
 import shlex
 import shutil
 import subprocess
+from datetime import datetime, timezone as datetime_timezone
 from pathlib import Path
+from urllib.parse import urlencode
 
 from django.contrib import messages
 from django.contrib.admin.views.decorators import staff_member_required
@@ -12,6 +14,7 @@ from django.conf import settings
 from django.http import FileResponse, Http404
 from django.db.models import Count, Q
 from django.shortcuts import get_object_or_404, redirect, render
+from django.urls import reverse
 from django.utils import timezone
 from django.views.decorators.http import require_POST
 
@@ -74,13 +77,18 @@ def dashboard(request):
         )
         host_config.next_run_at = _next_run_for_host(host_config)
         host_config.retention_warning = _retention_warning_for_host(host_config, _schedule_for_host(host_config))
+    action_items = _dashboard_action_items(hosts)
+    next_schedule_rows = _dashboard_next_schedule_rows()
+    recent_runs = BackupRun.objects.select_related("host", "snapshot").order_by("-created_at", "-id")[:6]
     stats_summary = collect_dashboard_stats(hosts=hosts, global_config=global_config)
     context = {
         "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],
+        "action_items": action_items,
+        "next_schedule_rows": next_schedule_rows,
+        "recent_runs": recent_runs,
         "counts": {
             "global_configs": GlobalConfig.objects.count(),
             "hosts": HostConfig.objects.count(),
@@ -104,6 +112,74 @@ def dashboard(request):
     return render(request, "pobsync_backend/dashboard.html", context)
 
 
+def _dashboard_action_items(hosts: list[HostConfig]) -> list[dict[str, object]]:
+    action_items: list[dict[str, object]] = []
+    for host_config in hosts:
+        if host_config.failed_run_count:
+            action_items.append(
+                {
+                    "host": host_config,
+                    "status": BackupRun.Status.FAILED,
+                    "label": "Failed runs",
+                    "message": f"{host_config.failed_run_count} failed run(s) need review.",
+                    "url": _runs_list_url(host=host_config.host, status="failed", review="needed"),
+                }
+            )
+        if host_config.warning_run_count:
+            action_items.append(
+                {
+                    "host": host_config,
+                    "status": BackupRun.Status.WARNING,
+                    "label": "Warnings",
+                    "message": f"{host_config.warning_run_count} run(s) completed with warnings.",
+                    "url": _runs_list_url(host=host_config.host, status="warning", review="needed"),
+                }
+            )
+        if host_config.retention_warning.has_warning:
+            action_items.append(
+                {
+                    "host": host_config,
+                    "status": BackupRun.Status.WARNING,
+                    "label": "Retention",
+                    "message": _retention_warning_summary(host_config.retention_warning),
+                    "url": reverse("host_detail", args=[host_config.host]),
+                }
+            )
+    return action_items
+
+
+def _runs_list_url(**params: str) -> str:
+    return f"{reverse('runs_list')}?{urlencode(params)}"
+
+
+def _dashboard_next_schedule_rows() -> list[dict[str, object]]:
+    rows = []
+    schedules = ScheduleConfig.objects.select_related("host").filter(enabled=True).order_by("host__host")
+    for schedule in schedules[:200]:
+        rows.append(
+            {
+                "schedule": schedule,
+                "next_run_at": _next_run_for_schedule(schedule, schedule.host),
+            }
+        )
+    rows.sort(key=lambda row: row["next_run_at"] or datetime.max.replace(tzinfo=datetime_timezone.utc))
+    return rows[:6]
+
+
+def _retention_warning_summary(retention_warning) -> str:
+    parts = []
+    if retention_warning.prune_exceeded:
+        parts.append(
+            f"Scheduled prune would delete {retention_warning.delete_count} snapshot(s), "
+            f"above max {retention_warning.max_delete}."
+        )
+    if retention_warning.incomplete_count:
+        parts.append(f"{retention_warning.incomplete_count} incomplete snapshot(s) need review.")
+    if retention_warning.error:
+        parts.append(str(retention_warning.error))
+    return " ".join(parts)
+
+
 @staff_member_required
 def changelog(request):
     changelog_path = Path(settings.BASE_DIR) / "CHANGELOG.md"