feat: display Copilot premium interactions quota on provider card

Copilot usage query API was implemented but never surfaced on the main
provider list. Add CopilotQuotaFooter component that auto-detects
github_copilot providers and displays premium interaction utilization
inline, reusing the existing TierBadge UI from SubscriptionQuotaFooter.

src/lib/query/copilot.ts

@@ -0,0 +1,52 @@
+import { useQuery } from "@tanstack/react-query";
+import { copilotGetUsage, copilotGetUsageForAccount } from "@/lib/api/copilot";
+import type { QuotaTier } from "@/types/subscription";
+
+const REFETCH_INTERVAL = 5 * 60 * 1000; // 5 minutes
+
+export interface CopilotQuota {
+  success: boolean;
+  plan: string | null;
+  resetDate: string | null;
+  tiers: QuotaTier[];
+  error: string | null;
+  queriedAt: number | null;
+}
+
+export function useCopilotQuota(accountId: string | null, enabled: boolean) {
+  return useQuery<CopilotQuota>({
+    queryKey: ["copilot", "quota", accountId ?? "default"],
+    queryFn: async (): Promise<CopilotQuota> => {
+      const usage = accountId
+        ? await copilotGetUsageForAccount(accountId)
+        : await copilotGetUsage();
+
+      const premium = usage.quota_snapshots.premium_interactions;
+      const utilization =
+        premium.entitlement > 0
+          ? ((premium.entitlement - premium.remaining) / premium.entitlement) *
+            100
+          : 0;
+
+      return {
+        success: true,
+        plan: usage.copilot_plan,
+        resetDate: usage.quota_reset_date,
+        tiers: [
+          {
+            name: "premium",
+            utilization,
+            resetsAt: usage.quota_reset_date,
+          },
+        ],
+        error: null,
+        queriedAt: Date.now(),
+      };
+    },
+    enabled,
+    refetchInterval: REFETCH_INTERVAL,
+    refetchOnWindowFocus: true,
+    staleTime: REFETCH_INTERVAL,
+    retry: 1,
+  });
+}