feat: add card rotation, customer lookup, and concurrent eligibility checks

Add encrypted card pool management, persisted card and outbound rotation, and per-card decline cooldowns. Improve customer and redemption-code lookup, recovery controls, and filtering; rebuild frontend assets and refresh mock screenshots.

Give read-only eligibility checks four independent slots so payment processing no longer blocks them. Cover concurrency, slot cleanup, card rotation, and lookup behavior with tests.

frontend/src/codeStatus.ts

@@ -0,0 +1,10 @@
+export const codeStatus: Record<
+  string,
+  { label: string; color: "default" | "primary" | "success" | "warning" }
+> = {
+  active: { label: "可使用", color: "primary" },
+  processing: { label: "处理中", color: "primary" },
+  succeeded: { label: "已完成", color: "success" },
+  review: { label: "待核实", color: "warning" },
+  revoked: { label: "已停用", color: "default" },
+};