Give the operator a provider-health readout

The per-user retry ledger has recorded every AI delivery outcome for a
long time, but no surface ever read it for the operator: a central
provider could fail on every call for weeks and the admin console said
nothing. The AI settings section now carries a health card, backed by a
new admin-only endpoint that folds the ledger into one row per provider
type: users tracked, users currently failing, the worst uninterrupted
failure run, and the last success and failure instants. Operator-managed
types sort first because their failure takes the shared fallback down
for everyone whose chain relies on it. Counts and timestamps only; the
response never names a user.

src/components/admin/provider-health-section.tsx

@@ -0,0 +1,130 @@
+"use client";
+
+import { useQuery } from "@tanstack/react-query";
+import { Activity } from "lucide-react";
+
+import { Badge } from "@/components/ui/badge";
+import { SettingsCard } from "@/components/settings/settings-card";
+import { SettingsCardHeader } from "@/components/settings/_card-header";
+import { useTranslations } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
+import { formatDateTime } from "@/lib/format";
+
+/**
+ * v1.37.31 — the delivery-health readout the `provider_health` ledger never
+ * had. The ledger records every AI call outcome per user and provider tag;
+ * before this card, a failing central provider was invisible until someone
+ * read the database. The card shows one row per provider type: how many
+ * users' chains touch it, how many of them are currently failing, the worst
+ * uninterrupted failure run, and the last success / failure instants.
+ */
+
+interface ProviderHealthRow {
+  providerType: string;
+  tracked: number;
+  failing: number;
+  maxConsecutiveFailures: number;
+  lastOkAt: string | null;
+  lastFailureAt: string | null;
+}
+
+export function ProviderHealthSection() {
+  const { t } = useTranslations();
+
+  const { data, isPending, isError } = useQuery({
+    queryKey: queryKeys.adminProviderHealth(),
+    queryFn: () =>
+      apiGet<{ providers: ProviderHealthRow[] }>("/api/admin/provider-health"),
+  });
+
+  const typeLabel = (type: string): string => {
+    switch (type) {
+      case "admin-openai":
+        return t("admin.providerHealth.typeAdminOpenai");
+      case "admin-codex":
+        return t("admin.providerHealth.typeAdminCodex");
+      case "openai":
+        return t("admin.providerHealth.typeOpenai");
+      case "anthropic":
+        return t("admin.providerHealth.typeAnthropic");
+      case "codex":
+        return t("admin.providerHealth.typeCodex");
+      case "local":
+        return t("admin.providerHealth.typeLocal");
+      case "openai-compatible":
+        return t("admin.providerHealth.typeGateway");
+      default:
+        return type;
+    }
+  };
+
+  const providers = data?.providers ?? [];
+
+  return (
+    <SettingsCard>
+      <SettingsCardHeader
+        icon={Activity}
+        title={t("admin.providerHealth.title")}
+        description={t("admin.providerHealth.description")}
+      />
+      {isPending ? (
+        <p className="text-muted-foreground text-sm">
+          {t("admin.providerHealth.loading")}
+        </p>
+      ) : isError ? (
+        <p className="text-muted-foreground text-sm">
+          {t("admin.providerHealth.loadError")}
+        </p>
+      ) : providers.length === 0 ? (
+        <p className="text-muted-foreground text-sm">
+          {t("admin.providerHealth.empty")}
+        </p>
+      ) : (
+        <ul className="flex flex-col gap-3" data-testid="provider-health-list">
+          {providers.map((p) => (
+            <li
+              key={p.providerType}
+              className="flex flex-wrap items-center justify-between gap-2 rounded-md border p-3"
+              data-provider-type={p.providerType}
+            >
+              <div className="flex min-w-0 flex-col gap-1">
+                <span className="text-sm font-medium">
+                  {typeLabel(p.providerType)}
+                </span>
+                <span className="text-muted-foreground text-xs">
+                  {t("admin.providerHealth.trackedUsers", {
+                    count: p.tracked,
+                  })}
+                  {p.lastOkAt
+                    ? ` · ${t("admin.providerHealth.lastOk", {
+                        at: formatDateTime(p.lastOkAt),
+                      })}`
+                    : ""}
+                  {p.failing > 0 && p.lastFailureAt
+                    ? ` · ${t("admin.providerHealth.lastFailure", {
+                        at: formatDateTime(p.lastFailureAt),
+                      })}`
+                    : ""}
+                </span>
+              </div>
+              {p.failing === 0 ? (
+                <Badge variant="secondary">
+                  {t("admin.providerHealth.statusHealthy")}
+                </Badge>
+              ) : (
+                <Badge variant="destructive">
+                  {t("admin.providerHealth.statusFailing", {
+                    failing: p.failing,
+                    tracked: p.tracked,
+                    run: p.maxConsecutiveFailures,
+                  })}
+                </Badge>
+              )}
+            </li>
+          ))}
+        </ul>
+      )}
+    </SettingsCard>
+  );
+}