把思考强度收到接口配置里，并支持分组、嗅探和切换同一接口下的模型。

预设不再保存思考强度。设置页会在首屏套用主题。

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/model-sniff-cache.test.ts

@@ -0,0 +1,45 @@
+import { beforeEach, describe, expect, it } from "vitest";
+import { readSniffModels, writeSniffModels } from "../web/model-sniff-cache.js";
+
+const store = new Map<string, string>();
+
+beforeEach(() => {
+  store.clear();
+  Object.defineProperty(globalThis, "sessionStorage", {
+    configurable: true,
+    value: {
+      getItem: (key: string) => store.get(key) ?? null,
+      setItem: (key: string, value: string) => {
+        store.set(key, value);
+      },
+      removeItem: (key: string) => {
+        store.delete(key);
+      },
+    },
+  });
+});
+
+describe("model sniff cache", () => {
+  it("keeps models for the current boot and drops them after restart", () => {
+    writeSniffModels("boot-a", "https://openrouter.ai/api/v1\nkey:abc", [
+      "google/gemini-3.8-flash",
+      "google/gemini-3.7-flash",
+    ]);
+
+    expect(
+      readSniffModels("boot-a", "https://openrouter.ai/api/v1\nkey:abc"),
+    ).toEqual(["google/gemini-3.8-flash", "google/gemini-3.7-flash"]);
+
+    expect(
+      readSniffModels("boot-b", "https://openrouter.ai/api/v1\nkey:abc"),
+    ).toEqual([]);
+  });
+
+  it("does not keep another boot's entries when writing again", () => {
+    writeSniffModels("boot-a", "slot", ["old-model"]);
+    writeSniffModels("boot-b", "slot", ["new-model"]);
+
+    expect(readSniffModels("boot-a", "slot")).toEqual([]);
+    expect(readSniffModels("boot-b", "slot")).toEqual(["new-model"]);
+  });
+});