feat: dashboard add platform order trend 7d

app/Http/Controllers/Admin/DashboardController.php

@@ -84,6 +84,39 @@ class DashboardController extends Controller
             ]
         );
 
+        // 趋势卡（最小可用）：近 7 天平台订单按天统计（订单数 + 已付金额）
+        $trendDays = 7;
+        $trendStart = now()->startOfDay()->subDays($trendDays - 1);
+        $trendEnd = now()->endOfDay();
+
+        $trendRawRows = PlatformOrder::query()
+            ->selectRaw("DATE(created_at) as d")
+            ->selectRaw('COUNT(*) as cnt')
+            ->selectRaw("SUM(CASE WHEN payment_status = 'paid' THEN paid_amount ELSE 0 END) as paid_sum")
+            ->whereBetween('created_at', [$trendStart, $trendEnd])
+            ->groupBy('d')
+            ->orderBy('d')
+            ->get();
+
+        $trendByDate = [];
+        foreach ($trendRawRows as $r) {
+            $trendByDate[(string) $r->d] = [
+                'date' => (string) $r->d,
+                'count' => (int) ($r->cnt ?? 0),
+                'paid_sum' => (float) ($r->paid_sum ?? 0),
+            ];
+        }
+
+        $platformOrderTrend7d = [];
+        for ($i = 0; $i < $trendDays; $i++) {
+            $day = $trendStart->copy()->addDays($i)->format('Y-m-d');
+            $platformOrderTrend7d[] = $trendByDate[$day] ?? [
+                'date' => $day,
+                'count' => 0,
+                'paid_sum' => 0.0,
+            ];
+        }
+
         $recentPlatformOrders = PlatformOrder::query()
             ->orderByDesc('id')
             ->limit(5)
@@ -111,6 +144,7 @@ class DashboardController extends Controller
         return view('admin.dashboard', [
             'adminName' => $admin->name,
             'stats' => $stats,
+            'platformOrderTrend7d' => $platformOrderTrend7d,
             'recentPlatformOrders' => $recentPlatformOrders,
             'planOrderShare' => $planOrderShare,
             'planIdToName' => $planIdToName,