persist gateway metrics across restarts

ui-src/src/App.tsx

@@ -23,6 +23,7 @@ type GatewayConfig = {
 
 type Metrics = {
   started_at?: string;
+  persistent_since?: string | null;
   total_proxy_request_count?: number;
   inspected_response_count?: number;
   matched_response_count?: number;
@@ -230,7 +231,7 @@ type ProfileProbePayload = {
 const pageCopy: Record<PageKey, { title: string; subtitle: string; index: string }> = {
   overview: {
     title: "概览",
-    subtitle: "当前 gateway 运行态和本次启动以来的累计统计。",
+    subtitle: "当前 gateway 运行态，以及基于持久请求记录回灌的累计统计。",
     index: "01",
   },
   requests: {
@@ -808,7 +809,7 @@ export default function App() {
                   </div>
                 </Card>
 
-                <Card title="Token Totals" hint="按本次 gateway 启动以来累计；后续可以接持久化统计。">
+                <Card title="Token Totals" hint="按持久请求记录累计；重启后会从 requests history 回灌。">
                   <div className="token-strip">
                     <TokenCard label="Input" value={numberFormat(effectiveInputTotal ?? 0)} />
                     <TokenCard label="Output" value={numberFormat(tokens.output_tokens || 0)} />
@@ -839,7 +840,8 @@ export default function App() {
                       rows={[
                         ["516 命中", numberFormat(metrics.reasoning_516_count || 0)],
                         ["516 占比", percent(metrics.reasoning_516_ratio || 0)],
-                        ["启动时间", timestamp(metrics.started_at)],
+                        ["累计起点", timestamp(metrics.persistent_since || metrics.started_at)],
+                        ["本次启动", timestamp(metrics.started_at)],
                         ["Config", status?.paths?.config_path || "-"],
                         ["备份", status?.state?.latest_backup_path || "-"],
                       ]}