Add chart freshness diagnostics

frontend/components/ops/__tests__/apiPerformanceTiming.test.ts

@@ -71,6 +71,26 @@ export function runTests() {
     /partial:\s*true/,
     "city detail batch proxy timeout fallback should preserve partial response semantics",
   );
+  assert.match(
+    detailBatchProxy,
+    /diagnostics:\s*{/,
+    "city detail batch proxy timeout fallback should include structured diagnostics",
+  );
+  assert.match(
+    detailBatchProxy,
+    /response_source:\s*"next_proxy_timeout"/,
+    "city detail batch proxy timeout diagnostics should identify the proxy timeout layer",
+  );
+  assert.match(
+    detailBatchProxy,
+    /partial_reason:\s*"proxy_timeout"/,
+    "city detail batch proxy timeout diagnostics should distinguish proxy timeout from backend partial timeout",
+  );
+  assert.match(
+    detailBatchProxy,
+    /city_status/,
+    "city detail batch proxy timeout diagnostics should include per-city status",
+  );
   assert.match(
     detailBatchProxy,
     /status:\s*200/,

frontend/components/ops/__tests__/opsFeedbackDropdown.test.ts

@@ -39,4 +39,15 @@ export function runTests() {
       source.includes("1500"),
     "ops feedback page must document fixed reward point guidelines",
   );
+  assert(
+    source.includes("feedbackFreshnessBadges") &&
+      source.includes("freshness?.live_path") &&
+      source.includes("freshness?.live_age_sec") &&
+      source.includes("sse_server_to_client_latency_sec") &&
+      source.includes("sse_collector_to_client_latency_sec") &&
+      source.includes("sse_source_to_collector_latency_sec") &&
+      source.includes("detail_batch_diagnostics") &&
+      source.includes("partial_reason"),
+    "ops feedback page must summarize live freshness, SSE latency and detail-batch diagnostics",
+  );
 }