perf(dashboard): 仪表盘加载提速

- models-dev 快照移出主 bundle（1.35MB→515KB），改为 /models-dev.json 运行时异步加载，就绪后重渲染
- Rust 启动时后台预热价格索引（warm_price_index），首次 get_summary 不再卡
- get_summary 扫描结果 8s TTL 缓存（按 home），切 tab/改范围复用；刷新按钮 refresh=true 强制重扫

src/lib/models-dev.ts

@@ -1,9 +1,15 @@
-import snapshot from "./models-dev.json";
-
 /**
  * Compact per-model reference data from models.dev
  * (see scripts/fetch-models-dev.mjs).
+ *
+ * The snapshot (~1.3 MB JSON) is NOT bundled into the main chunk anymore:
+ * parsing a 1.3 MB JSON literal at startup blocks first paint. It is served
+ * as a static asset (`/models-dev.json`) and loaded once in the background.
+ * `getModelRef` stays synchronous and returns undefined until the index is
+ * ready — callers already fall back to defaults — and `modelsDevReady()`
+ * lets the app re-render once the index arrives.
  */
+
 export interface ModelCost {
   input?: number;
   output?: number;
@@ -23,22 +29,58 @@ export interface ModelRef {
   cost?: ModelCost;
 }
 
-const raw = snapshot as Record<string, unknown>;
+let byLowerKey: Record<string, ModelRef> | null = null;
+let readyListeners: Array<() => void> = [];
 
-// Drop the "last_updated" metadata key; the rest is "<provider>/<model>".
-const data: Record<string, ModelRef> = {};
-for (const [key, value] of Object.entries(raw)) {
-  if (key !== "last_updated" && value && typeof value === "object") {
-    data[key] = value as ModelRef;
+function buildIndex(raw: Record<string, unknown>) {
+  const data: Record<string, ModelRef> = {};
+  for (const [key, value] of Object.entries(raw)) {
+    if (key !== "last_updated" && value && typeof value === "object") {
+      data[key] = value as ModelRef;
+    }
   }
+  // models.dev keys are "<lab>/<model>" and may be mixed-case (e.g.
+  // "minimax/MiniMax-M3"), while provider APIs return bare model ids
+  // (e.g. "kimi-k2.5"). Index lowercase for tolerant matching.
+  const lower: Record<string, ModelRef> = {};
+  for (const [key, value] of Object.entries(data)) {
+    lower[key.toLowerCase()] = value;
+  }
+  return lower;
 }
 
-// models.dev keys are "<lab>/<model>" and may be mixed-case (e.g.
-// "minimax/MiniMax-M3"), while provider APIs return bare model ids
-// (e.g. "kimi-k2.5"). Index lowercase for tolerant matching.
-const byLowerKey: Record<string, ModelRef> = {};
-for (const [key, value] of Object.entries(data)) {
-  byLowerKey[key.toLowerCase()] = value;
+let loadPromise: Promise<void> | null = null;
+
+export function modelsDevReady(): Promise<void> {
+  if (!loadPromise) {
+    loadPromise = fetch(`${import.meta.env.BASE_URL}models-dev.json`)
+      .then((r) => {
+        if (!r.ok) throw new Error(`models-dev.json HTTP ${r.status}`);
+        return r.json() as Promise<Record<string, unknown>>;
+      })
+      .then((raw) => {
+        byLowerKey = buildIndex(raw);
+        const listeners = readyListeners;
+        readyListeners = [];
+        for (const cb of listeners) cb();
+      })
+      .catch((err) => {
+        // A failed load is permanent for this session: fall back to defaults.
+        byLowerKey = {};
+        loadPromise = null; // allow one retry next time
+        console.warn("models-dev.json load failed:", err);
+      });
+  }
+  return loadPromise;
+}
+
+/** Register a callback invoked once the models.dev index is ready. */
+export function onModelsDevReady(cb: () => void): void {
+  if (byLowerKey) {
+    cb();
+    return;
+  }
+  readyListeners.push(cb);
 }
 
 /**
@@ -49,7 +91,7 @@ for (const [key, value] of Object.entries(data)) {
  */
 export function getModelRef(modelId: string): ModelRef | undefined {
   const id = modelId.trim().toLowerCase();
-  if (!id) return undefined;
+  if (!id || !byLowerKey) return undefined;
   const exact = byLowerKey[id];
   if (exact) return exact;
   const suffix = `/${id}`;