详情页返回按来源回到上一页并改用浏览器原生返回

- GameDetailPage 左上角「返回游戏广场」简化为「返回」，不再写死跳广场
- 详情/游玩页返回优先 window.history.back()，由 popstate 还原真实来源页（我的游戏/广场）
- activeAppPageRoutes 给应用历史条目补深度标记并新增 hasAppHistoryBackEntry()
- 深链直开等无可回退条目时用 replaceAppHistoryPath 兜底回广场或详情
- 新增 activeAppPageRoutes 深度语义用例与 PlatformEntryActiveFlowShell「游戏详情返回」两条用例
- 同步里程碑文档 2026-09-30 与 pitfalls 同日条目

src/routing/activeAppPageRoutes.test.ts

@@ -3,6 +3,7 @@
 import { describe, expect, it } from 'vitest';
 
 import {
+  hasAppHistoryBackEntry,
   isAppHistoryState,
   isKnownMainAppPagePath,
   pushAppHistoryPath,
@@ -75,4 +76,16 @@ describe('appPageRoutes', () => {
     expect(window.location.pathname).toBe('/project');
     expect(window.location.search).toContain('hostShell=tauri_desktop');
   });
+
+  it('只有应用内推送过上一页时才算可原生返回', () => {
+    window.history.replaceState(null, '', '/games/detail?id=game-1');
+    expect(hasAppHistoryBackEntry()).toBe(false);
+
+    window.history.replaceState(null, '', '/games/mine');
+    pushAppHistoryPath('/games/detail?id=game-1');
+    expect(hasAppHistoryBackEntry()).toBe(true);
+
+    replaceAppHistoryPath('/games/detail?id=game-2');
+    expect(hasAppHistoryBackEntry()).toBe(true);
+  });
 });

src/routing/activeAppPageRoutes.ts

@@ -26,6 +26,7 @@ const ROUTE_STAGE_BY_PATH = new Map(
 const APP_RUNTIME_CONTEXT_QUERY_KEYS =
   HOST_BRIDGE_PRESERVED_RUNTIME_CONTEXT_QUERY_KEYS;
 export const APP_HISTORY_STATE_KEY = '__genarrativeAppHistoryEntry';
+const APP_HISTORY_STATE_DEPTH_KEY = '__genarrativeAppHistoryDepth';
 
 export function normalizeAppPath(pathname: string) {
   const trimmedPathname = pathname.trim().toLowerCase();
@@ -92,7 +93,7 @@ function writeAppHistoryPath(path: string, mode: 'push' | 'replace') {
     return;
   }
 
-  const state = buildAppHistoryState();
+  const state = buildAppHistoryState(mode);
   if (mode === 'replace') {
     window.history.replaceState(state, '', nextRelativeUrl);
     return;
@@ -108,14 +109,37 @@ export function isAppHistoryState(state: unknown) {
   );
 }
 
-function buildAppHistoryState() {
+/**
+ * 当前历史条目是不是应用内导航写入的、且存在可回退的上一页。
+ * 直接打开深链时浏览器条目不是应用写入的，此时返回需要走兜底路径，
+ * 否则 `history.back()` 会直接退出应用。
+ */
+export function hasAppHistoryBackEntry() {
+  const state = window.history.state;
+  if (!isAppHistoryState(state)) {
+    return false;
+  }
+  return readAppHistoryDepth(state as Record<string, unknown>) > 0;
+}
+
+function readAppHistoryDepth(state: Record<string, unknown>) {
+  const depth = state[APP_HISTORY_STATE_DEPTH_KEY];
+  return typeof depth === 'number' && Number.isFinite(depth) ? depth : 0;
+}
+
+function buildAppHistoryState(mode: 'push' | 'replace') {
   const currentState =
     window.history.state && typeof window.history.state === 'object'
       ? window.history.state
       : {};
+  const currentDepth = readAppHistoryDepth(
+    currentState as Record<string, unknown>,
+  );
   return {
     ...currentState,
     [APP_HISTORY_STATE_KEY]: true,
+    [APP_HISTORY_STATE_DEPTH_KEY]:
+      mode === 'push' ? currentDepth + 1 : currentDepth,
   };
 }