fix(agent): 切换会话不再重挂载整页、不重播入场动画

控制台主内容区按 pathname 重挂载,每换一个会话整页透明 + 模糊再淡入,
左栏滚动、分页、展开状态全部丢失。智能体列表页与会话页共用一个 key。

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Cxwgnn2pbzQ7rXv3rq7fei

apps/web/app/components/agent/agent-nav.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from "vitest";
+import { isAgentPage, outletKey } from "./agent-store.ts";
+
+// 智能体页面切换的状态逻辑:整页重挂载 key、分栏与 URL、草稿、滚动策略、快捷键在智能体页面的行为。
+
+describe("主内容区重挂载 key", () => {
+  it("列表页与各会话页共用一个 key,切换会话不重挂载", () => {
+    expect(outletKey("/console/agent")).toBe("/console/agent");
+    expect(outletKey("/console/agent/0b1c")).toBe("/console/agent");
+    expect(outletKey("/console/agent/9f2e")).toBe(outletKey("/console/agent/0b1c"));
+  });
+  it("其它页面仍按路径重挂载", () => {
+    expect(outletKey("/console/library")).toBe("/console/library");
+    expect(outletKey("/console/agents-x")).toBe("/console/agents-x");
+    expect(isAgentPage("/console/agentx")).toBe(false);
+  });
+});