feat(frontend): add polling job queue ui

frontend/src/types.ts

@@ -0,0 +1,45 @@
+export type JobStatus = "queued" | "running" | "succeeded" | "failed";
+
+export type Job = {
+  id: string;
+  type: string;
+  payload: Record<string, unknown>;
+  status: JobStatus;
+  priority: number;
+  available_at: string;
+  attempts: number;
+  max_attempts: number;
+  idempotency_key: string | null;
+  locked_by: string | null;
+  locked_until: string | null;
+  last_error: string;
+  result: unknown;
+  created_at: string;
+  updated_at: string;
+  finished_at: string | null;
+};
+
+export type JobEvent = {
+  id: number;
+  job: string;
+  type: string;
+  attempt: number;
+  worker_id: string | null;
+  message: string;
+  data: Record<string, unknown>;
+  created_at: string;
+};
+
+export type JobStats = {
+  total: number;
+  by_status: Record<JobStatus, number>;
+  overdue_running: number;
+  retries_pending: number;
+  oldest_queued_at: string | null;
+};
+
+export type Health = {
+  ok: boolean;
+  database: string;
+  detail?: string;
+};