补强原生壳事件注入链路

移动壳 ShellApp 补充生命周期网络和返回栈事件注入测试

移动壳网络状态重放失败改为显式日志记录

桌面壳生命周期和拖拽图片事件失败改为统一日志记录

两端配置门禁反查 HostBridge 事件注入和失败处理

宿主壳协议和共享决策记录同步事件失败规则

apps/desktop-shell/scripts/check-config.mjs

@@ -2213,7 +2213,7 @@ const requiredRustHostSnippets = [
   'should_replay_desktop_webview_state_on_page_load',
   'PageLoadEvent::Finished',
   'replay_desktop_webview_state',
-  'log_desktop_webview_state_replay_result',
+  'log_desktop_host_event_result',
   'window.is_focused()',
   'window.is_visible()',
   'window.is_minimized()',
@@ -2228,6 +2228,7 @@ const requiredRustHostSnippets = [
   "window.addEventListener('popstate'",
   '__genarrativeDesktopHistoryIndex',
   'file.imageDropped',
+  'emit_desktop_image_drop_event(&drop_window, paths, drop_position)',
   'app.notification().builder()',
   'desktop_entry_url_with_host_context',
   'desktop_h5_url_with_host_context',
@@ -2680,7 +2681,7 @@ for (const appSetupSnippet of [
   'desktop_new_window_response',
   'register_desktop_network_events(&window)?',
   'register_desktop_navigation_events(&window)?',
-  'log_desktop_webview_state_replay_result(',
+  'log_desktop_host_event_result(',
 ]) {
   if (!app.includes(appSetupSnippet)) {
     throw new Error(`desktop shell app.rs missing setup snippet ${appSetupSnippet}`);
@@ -2706,6 +2707,8 @@ for (const blockedLifecycleSnippet of [
   'let _ = register_desktop_network_events(window)',
   'let _ = register_desktop_navigation_events(window)',
   'let _ = emit_current_desktop_lifecycle_event(window)',
+  'let _ = emit_current_desktop_lifecycle_event(&lifecycle_window)',
+  'let _ = emit_desktop_image_drop_event(&drop_window',
 ]) {
   if (rustHostSource.includes(blockedLifecycleSnippet)) {
     throw new Error(

apps/desktop-shell/src-tauri/src/app.rs

@@ -9,8 +9,8 @@ use crate::shell::tray::{
 };
 use crate::shell::webview::{
     desktop_window_config_with_runtime_platform, emit_current_desktop_lifecycle_event,
-    desktop_external_navigation_url,
-    log_desktop_webview_state_replay_result, open_desktop_external_navigation,
+    desktop_external_navigation_url, log_desktop_host_event_result,
+    open_desktop_external_navigation,
     open_normalized_desktop_external_url, register_desktop_file_drop_events,
     register_desktop_lifecycle_events, register_desktop_navigation_events,
     register_desktop_network_events, replay_desktop_webview_state,
@@ -103,7 +103,7 @@ pub(crate) fn run() {
                 .build()?;
             register_desktop_window_close_events(&window, tray_registered);
             register_desktop_lifecycle_events(&window);
-            log_desktop_webview_state_replay_result(
+            log_desktop_host_event_result(
                 "app.lifecycle",
                 emit_current_desktop_lifecycle_event(&window),
             );

apps/desktop-shell/src-tauri/src/shell/file_drop.rs

@@ -1,5 +1,6 @@
 use crate::host_bridge::files::{import_image_file_payload, import_image_mime_type};
 use crate::shell::events::host_bridge_event_script;
+use crate::shell::lifecycle::log_desktop_host_event_result;
 use serde_json::Value;
 use std::path::PathBuf;
 use tauri::{DragDropEvent, WebviewWindow, WindowEvent};
@@ -33,7 +34,10 @@ pub(crate) fn register_desktop_file_drop_events(window: &WebviewWindow) {
     window.on_window_event(move |event| {
         if let WindowEvent::DragDrop(DragDropEvent::Drop { paths, position }) = event {
             let drop_position = (position.x.round() as i32, position.y.round() as i32);
-            let _ = emit_desktop_image_drop_event(&drop_window, paths, drop_position);
+            log_desktop_host_event_result(
+                "file.imageDropped",
+                emit_desktop_image_drop_event(&drop_window, paths, drop_position),
+            );
         }
     });
 }

apps/desktop-shell/src-tauri/src/shell/lifecycle.rs

@@ -88,7 +88,10 @@ pub(crate) fn register_desktop_lifecycle_events(window: &WebviewWindow) {
     let lifecycle_window = window.clone();
     window.on_window_event(move |event| {
         if matches!(event, WindowEvent::Focused(_) | WindowEvent::Resized(_)) {
-            let _ = emit_current_desktop_lifecycle_event(&lifecycle_window);
+            log_desktop_host_event_result(
+                "app.lifecycle",
+                emit_current_desktop_lifecycle_event(&lifecycle_window),
+            );
         }
     });
 }
@@ -97,29 +100,29 @@ pub(crate) fn should_replay_desktop_webview_state_on_page_load(event: PageLoadEv
     event == PageLoadEvent::Finished
 }
 
-pub(crate) fn log_desktop_webview_state_replay_result(
+pub(crate) fn log_desktop_host_event_result(
     label: &'static str,
     result: tauri::Result<()>,
 ) -> bool {
     match result {
         Ok(()) => true,
         Err(error) => {
-            eprintln!("desktop webview state replay failed for {label}: {error}");
+            eprintln!("desktop host event failed for {label}: {error}");
             false
         }
     }
 }
 
 pub(crate) fn replay_desktop_webview_state(window: &WebviewWindow) {
-    log_desktop_webview_state_replay_result(
+    log_desktop_host_event_result(
         "app.lifecycle",
         emit_current_desktop_lifecycle_event(window),
     );
-    log_desktop_webview_state_replay_result(
+    log_desktop_host_event_result(
         "network.statusChanged",
         register_desktop_network_events(window),
     );
-    log_desktop_webview_state_replay_result(
+    log_desktop_host_event_result(
         "navigation.canGoBack",
         register_desktop_navigation_events(window),
     );
@@ -140,9 +143,9 @@ mod tests {
     }
 
     #[test]
-    fn desktop_state_replay_result_reports_success_and_failure() {
-        assert!(log_desktop_webview_state_replay_result("network", Ok(())));
-        assert!(!log_desktop_webview_state_replay_result(
+    fn desktop_host_event_result_reports_success_and_failure() {
+        assert!(log_desktop_host_event_result("network", Ok(())));
+        assert!(!log_desktop_host_event_result(
             "navigation",
             Err(tauri::Error::AssetNotFound("navigation".to_string()))
         ));

apps/desktop-shell/src-tauri/src/shell/webview.rs

@@ -1,6 +1,6 @@
 pub(crate) use crate::shell::file_drop::register_desktop_file_drop_events;
 pub(crate) use crate::shell::lifecycle::{
-    emit_current_desktop_lifecycle_event, log_desktop_webview_state_replay_result,
+    emit_current_desktop_lifecycle_event, log_desktop_host_event_result,
     register_desktop_lifecycle_events, replay_desktop_webview_state,
     should_replay_desktop_webview_state_on_page_load,
 };

apps/mobile-shell/scripts/check-config.mjs

@@ -1135,6 +1135,8 @@ for (const snippet of [
   'injectHostBridgeEvent',
   'injectLifecycleEvent',
   'injectNetworkStatusEvent',
+  'logMobileHostEventFailure',
+  "logMobileHostEventFailure('network.statusChanged', error)",
   'handleWebViewLoad',
   'onLoad={handleWebViewLoad}',
   'navigation.canGoBack',
@@ -1872,6 +1874,20 @@ for (const snippet of [
   }
 }
 
+for (const snippet of [
+  "hostBridgeEvent('app.lifecycle')",
+  "hostBridgeEvent('network.statusChanged')",
+  "lastHostBridgeEvent('navigation.canGoBack')",
+  "shellHarness.appStateListeners[0]?.('background')",
+  'shellHarness.networkListeners[0]?.({',
+  "type: 'genarrative.mobile.historyState'",
+  'mobile host event failed for network.statusChanged',
+]) {
+  if (!shellAppTestSource.includes(snippet)) {
+    throw new Error(`mobile shell ShellApp HostBridge event test missing ${snippet}`);
+  }
+}
+
 if (
   !dispatchSource.includes('scanMobileHostBridgeQrCode(request)') ||
   dispatchSource.includes('ok(request, await scanQrCode())')

apps/mobile-shell/src/shell/ShellApp.test.tsx

@@ -1,6 +1,7 @@
 /* @vitest-environment jsdom */
 
 import { render, waitFor } from '@testing-library/react';
+import * as Network from 'expo-network';
 import React from 'react';
 import { afterEach, describe, expect, test, vi } from 'vitest';
 
@@ -11,17 +12,23 @@ import {
 } from '../../../../packages/shared/src/contracts/hostBridge';
 
 const shellHarness = vi.hoisted(() => {
+  const appStateListeners = [] as Array<(state: string) => void>;
   const webViewProps = { current: null as Record<string, unknown> | null };
   const cameraViewProps = { current: null as Record<string, unknown> | null };
   const injectedScripts = [] as string[];
+  const networkListeners = [] as Array<(state: Record<string, unknown>) => void>;
 
   return {
+    appStateListeners,
     cameraViewProps,
     injectedScripts,
+    networkListeners,
     reset() {
+      appStateListeners.length = 0;
       webViewProps.current = null;
       cameraViewProps.current = null;
       injectedScripts.length = 0;
+      networkListeners.length = 0;
     },
     webViewProps,
   };
@@ -95,9 +102,12 @@ vi.mock('expo-linking', () => ({
 }));
 
 vi.mock('expo-network', () => ({
-  addNetworkStateListener: vi.fn(() => ({
-    remove: vi.fn(),
-  })),
+  addNetworkStateListener: vi.fn((listener) => {
+    shellHarness.networkListeners.push(listener);
+    return {
+      remove: vi.fn(),
+    };
+  }),
   getNetworkStateAsync: vi.fn(async () => ({
     isConnected: true,
     isInternetReachable: true,
@@ -158,7 +168,10 @@ vi.mock('react-native-webview', () => ({
 
 vi.mock('react-native', () => ({
   AppState: {
-    addEventListener: vi.fn(() => ({ remove: vi.fn() })),
+    addEventListener: vi.fn((_event, listener) => {
+      shellHarness.appStateListeners.push(listener);
+      return { remove: vi.fn() };
+    }),
     currentState: 'active',
   },
   BackHandler: {
@@ -217,6 +230,30 @@ function extractInjectedHostBridgeMessage(script: string) {
   return JSON.parse(JSON.parse(encodedMessage)) as unknown;
 }
 
+function hostBridgeMessages() {
+  return shellHarness.injectedScripts.map(extractInjectedHostBridgeMessage);
+}
+
+function hostBridgeEvent(eventName: string) {
+  return hostBridgeMessages().find(
+    (message) =>
+      typeof message === 'object' &&
+      message !== null &&
+      (message as { event?: unknown }).event === eventName,
+  ) as { event: string; payload?: unknown } | undefined;
+}
+
+function lastHostBridgeEvent(eventName: string) {
+  return hostBridgeMessages()
+    .filter(
+      (message) =>
+        typeof message === 'object' &&
+        message !== null &&
+        (message as { event?: unknown }).event === eventName,
+    )
+    .at(-1) as { event: string; payload?: unknown } | undefined;
+}
+
 afterEach(() => {
   shellHarness.reset();
   vi.resetModules();
@@ -284,3 +321,132 @@ describe('ShellApp QR scanner HostBridge flow', () => {
     });
   });
 });
+
+describe('ShellApp HostBridge event injection', () => {
+  test('AppState changes inject app.lifecycle events into WebView', async () => {
+    const ShellApp = await importShellApp();
+    render(<ShellApp />);
+
+    await waitFor(() => {
+      expect(shellHarness.appStateListeners.length).toBeGreaterThan(0);
+    });
+
+    shellHarness.injectedScripts.length = 0;
+    shellHarness.appStateListeners[0]?.('background');
+
+    const event = hostBridgeEvent('app.lifecycle');
+    expect(event).toMatchObject({
+      event: 'app.lifecycle',
+      payload: {
+        state: 'background',
+        focused: false,
+        nativeState: 'background',
+      },
+    });
+  });
+
+  test('native network listener injects network.statusChanged events into WebView', async () => {
+    const ShellApp = await importShellApp();
+    render(<ShellApp />);
+
+    await waitFor(() => {
+      expect(shellHarness.networkListeners.length).toBeGreaterThan(0);
+    });
+
+    shellHarness.injectedScripts.length = 0;
+    shellHarness.networkListeners[0]?.({
+      isConnected: false,
+      isInternetReachable: false,
+      type: 'NONE',
+    });
+
+    const event = hostBridgeEvent('network.statusChanged');
+    expect(event).toMatchObject({
+      event: 'network.statusChanged',
+      payload: {
+        isConnected: false,
+        isInternetReachable: false,
+        connectionType: 'none',
+        nativeType: 'NONE',
+      },
+    });
+  });
+
+  test('native and H5 navigation state inject combined navigation.canGoBack events', async () => {
+    const ShellApp = await importShellApp();
+    render(<ShellApp />);
+
+    const webViewProps = shellHarness.webViewProps.current as {
+      onMessage?: (event: {
+        nativeEvent: {
+          data: string;
+          url: string;
+        };
+      }) => void;
+      onNavigationStateChange?: (event: { canGoBack: boolean }) => void;
+      source?: { uri?: string };
+    };
+    const webViewUrl = webViewProps.source?.uri ?? 'https://app.genarrative.world/';
+
+    shellHarness.injectedScripts.length = 0;
+    webViewProps.onNavigationStateChange?.({ canGoBack: true });
+    expect(lastHostBridgeEvent('navigation.canGoBack')).toMatchObject({
+      event: 'navigation.canGoBack',
+      payload: {
+        canGoBack: true,
+      },
+    });
+
+    shellHarness.injectedScripts.length = 0;
+    webViewProps.onNavigationStateChange?.({ canGoBack: false });
+    webViewProps.onMessage?.({
+      nativeEvent: {
+        data: JSON.stringify({
+          type: 'genarrative.mobile.historyState',
+          canGoBack: true,
+        }),
+        url: webViewUrl,
+      },
+    });
+
+    expect(lastHostBridgeEvent('navigation.canGoBack')).toMatchObject({
+      event: 'navigation.canGoBack',
+      payload: {
+        canGoBack: true,
+      },
+    });
+  });
+
+  test('load-time network event replay failure is logged instead of hidden', async () => {
+    const ShellApp = await importShellApp();
+    render(<ShellApp />);
+
+    const webViewProps = shellHarness.webViewProps.current as {
+      onLoad?: (event: {
+        nativeEvent: {
+          url: string;
+        };
+      }) => void;
+      source?: { uri?: string };
+    };
+    const webViewUrl = webViewProps.source?.uri ?? 'https://app.genarrative.world/';
+    const networkError = new Error('network replay failed');
+    const warnSpy = vi.spyOn(console, 'warn').mockImplementation(() => undefined);
+    vi.mocked(Network.getNetworkStateAsync).mockRejectedValueOnce(networkError);
+
+    webViewProps.onLoad?.({
+      nativeEvent: {
+        url: webViewUrl,
+      },
+    });
+
+    await waitFor(() => {
+      expect(warnSpy).toHaveBeenCalledWith(
+        'mobile host event failed for network.statusChanged',
+        networkError,
+      );
+    });
+
+    warnSpy.mockRestore();
+  });
+});

apps/mobile-shell/src/shell/ShellApp.tsx

@@ -73,6 +73,10 @@ function buildHostBridgeEventScript(event: HostBridgeEventName, payload: unknown
   });
 }
 
+function logMobileHostEventFailure(label: HostBridgeEventName, error: unknown) {
+  console.warn(`mobile host event failed for ${label}`, error);
+}
+
 type MobileWebViewLoadErrorEvent = {
   nativeEvent: {
     url: string;
@@ -290,7 +294,9 @@ export default function ShellApp() {
     injectLifecycleEvent(AppState.currentState);
     void getMobileNetworkStatus()
       .then(injectNetworkStatusEvent)
-      .catch(() => undefined);
+      .catch((error: unknown) => {
+        logMobileHostEventFailure('network.statusChanged', error);
+      });
   };
   const handleWebViewLoadError = (event: MobileWebViewLoadErrorEvent) => {
     resetNavigationCanGoBack();

docs/project-memory/shared-memory/decision-log.md

@@ -2852,9 +2852,16 @@
 - 影响范围：`apps/desktop-shell/src-tauri/src/host_bridge/badge.rs`、`apps/desktop-shell/src-tauri/src/host_bridge/notifications.rs`、`apps/desktop-shell/src-tauri/src/host_bridge/dispatch.rs`、`apps/desktop-shell/scripts/check-config.mjs`、`docs/project-memory/shared-memory/decision-log.md`。
 - 验证方式：`npm run desktop-shell:typecheck`、`npm run desktop-shell:test`、`npm run check:native-shells`、`npm run check:encoding`、`git diff --check`。
 
-## 2026-06-20 桌面壳 HostBridge 事件注册失败不可静默
+## 2026-06-20 桌面壳 HostBridge 事件失败不可静默
 
-- 背景：Tauri 桌面壳已经声明 `host.events`、`app.lifecycle`、`network.statusChanged` 和 `navigation.canGoBack`，H5 会据此订阅生命周期、网络和返回栈事件；如果 WebView 事件脚本注册失败仍被静默忽略，H5 会误以为宿主能力可用。
-- 决策：桌面壳启动阶段安装 `network.statusChanged` 和 `navigation.canGoBack` 脚本失败时直接阻断启动；生命周期首发和页面加载重放阶段的 `app.lifecycle`、`network.statusChanged`、`navigation.canGoBack` 失败必须通过统一 helper 记录日志，不允许 `let _ = register_desktop_*` 或 `let _ = emit_current_*` 静默吞错。配置检查反查该错误处理路径。
-- 影响范围：`apps/desktop-shell/src-tauri/src/app.rs`、`apps/desktop-shell/src-tauri/src/shell/lifecycle.rs`、`apps/desktop-shell/scripts/check-config.mjs`、宿主壳能力统一协议文档。
+- 背景：Tauri 桌面壳已经声明 `host.events`、`app.lifecycle`、`network.statusChanged`、`navigation.canGoBack` 和 `file.imageDropped`，H5 会据此订阅生命周期、网络、返回栈和拖拽图片事件；如果 WebView 事件脚本注册或发射失败仍被静默忽略，H5 会误以为宿主能力可用。
+- 决策：桌面壳启动阶段安装 `network.statusChanged` 和 `navigation.canGoBack` 脚本失败时直接阻断启动；生命周期首发、页面加载重放、窗口生命周期事件和拖拽图片事件阶段的 `app.lifecycle`、`network.statusChanged`、`navigation.canGoBack`、`file.imageDropped` 失败必须通过统一 helper 记录日志，不允许 `let _ = register_desktop_*`、`let _ = emit_current_*` 或 `let _ = emit_desktop_image_drop_event` 静默吞错。配置检查反查该错误处理路径。
+- 影响范围：`apps/desktop-shell/src-tauri/src/app.rs`、`apps/desktop-shell/src-tauri/src/shell/lifecycle.rs`、`apps/desktop-shell/src-tauri/src/shell/file_drop.rs`、`apps/desktop-shell/src-tauri/src/shell/webview.rs`、`apps/desktop-shell/scripts/check-config.mjs`、宿主壳能力统一协议文档。
 - 验证方式：`cargo test --manifest-path apps/desktop-shell/src-tauri/Cargo.toml`、`npm run check:native-shells`、`npm run check:encoding`、`git diff --check`。
+
+## 2026-06-20 移动壳 ShellApp HostBridge 事件注入必须可执行覆盖
+
+- 背景：Expo 移动壳声明 `host.events`、`app.lifecycle`、`network.statusChanged` 和 `navigation.canGoBack`，但 ShellApp 真实 AppState、Network 和 WebView 返回栈注入链路需要和扫码链路一样有可执行测试覆盖，不能只靠字符串门禁。
+- 决策：`apps/mobile-shell/src/shell/ShellApp.test.tsx` 必须覆盖 AppState 到 `app.lifecycle`、Expo Network listener 到 `network.statusChanged`、WebView native / H5 history 合成到 `navigation.canGoBack` 的真实注入脚本；页面 load 后网络状态重放失败必须记录日志，不允许静默 `.catch(() => undefined)`。移动壳配置检查反查这些测试片段和失败日志 helper。
+- 影响范围：`apps/mobile-shell/src/shell/ShellApp.tsx`、`apps/mobile-shell/src/shell/ShellApp.test.tsx`、`apps/mobile-shell/scripts/check-config.mjs`、宿主壳能力统一协议文档。
+- 验证方式：`npm run mobile-shell:test -- src/shell/ShellApp.test.tsx`、`npm run mobile-shell:typecheck`、`npm run check:native-shells`、`npm run check:encoding`、`git diff --check`。

docs/【前端架构】宿主壳能力统一协议-2026-06-17.md

@@ -58,7 +58,7 @@ Tauri 桌面壳启动时必须按 `label="main"` 解析 `tauri.conf.json` 主窗
 - `subscribeHostAppLifecycle()`：原生 App 宿主的受控生命周期事件入口。Expo 移动壳和 Tauri 桌面壳都声明 `host.events`，表示宿主会通过 HostBridge message 派发事件；其中 Expo 移动壳通过 React Native `AppState` 派发 `app.lifecycle`，Tauri 桌面壳通过主窗口 focus / blur、托盘隐藏 / 恢复和页面加载重放派发同名事件。桌面壳不会把 hidden、minimized 或 tray 扩成新的 `state`，而是读取 `is_visible()`、`is_minimized()`、`is_focused()` 后统一归一为 `active` / `inactive` / `background`，并只把 `hidden`、`minimized`、`focused`、`blurred` 放进 `nativeState` 用于排障。`host.events` 不作为 request method，也不开放 Tauri event 插件或 React Native 私有事件 API。H5 只依赖统一的 `active` / `inactive` / `background` 状态和 `focused` 布尔值，原生细分状态只放在 `nativeState` 用于排障，不作为业务分支依据。H5 统一通过 `useHostLifecycleActive()` 把宿主状态折算为运行态可播放状态；WebAudio 背景音乐和固定玩法 `<audio>` 背景音乐都必须按该状态暂停 / 恢复，宿主进入后台、inactive 或窗口失焦时暂停，回到 active 且 focused 后只在原运行态、音源和用户音量仍允许时恢复。
 - `getHostNetworkStatus()` / `subscribeHostNetworkStatusChange()`：原生 App 宿主的受控网络状态入口。Expo 移动壳通过 `expo-network` 查询并订阅真实系统网络状态；Tauri 桌面壳从 `WEB_APP_ORIGIN` 解析主站 host / port 后按共享契约 `HOST_BRIDGE_DESKTOP_NETWORK_CHECK_TIMEOUT_MS` 做短超时 TCP 可达性查询，并在主 WebView 内监听 `online` / `offline` 注入变化事件。H5 只依赖统一的 `isConnected`、`isInternetReachable` 和连接类型，不直接读取平台私有网络 API。平台外部生成队列概览通过 `useHostNetworkOnline()` 消费该状态，宿主未声明网络能力时保持原轮询行为，宿主明确离线或不可达时暂停轮询，恢复在线后重新刷新；该状态不替代后端队列事实或生成结果回读。
 - `subscribeHostNavigationCanGoBack()` / `useHostNavigationCanGoBack()`：原生 App 宿主的受控返回栈状态入口。H5 只有在宿主同时声明 `host.events` 和 `navigation.canGoBack` 时才订阅该事件；Expo 移动壳和 Tauri 桌面壳注入的状态只表示当前 H5 文档路由栈或宿主已归一后的返回状态，不让 H5 读取任意原生 back-forward list。主 App 在原生壳内直达非平台首页、非 runtime 的二级 H5 route 且当前 history state 没有应用导航标记时，会先把当前条目替换为 `/` 返回锚点，再把当前路径连同已保留的宿主 query 推回 history；普通浏览器、小程序、runtime 路由、已有应用 history 或不支持返回栈事件的裁剪壳不触发该补齐。
-  声明 `host.events`、`app.lifecycle`、`network.statusChanged` 或 `navigation.canGoBack` 后，宿主壳必须把对应 WebView 事件脚本注册失败显式失败或记录日志；启动阶段无法安装网络 / 返回栈事件时不得继续以半可用状态运行，页面重放阶段不得静默吞掉失败。
+  声明 `host.events`、`app.lifecycle`、`network.statusChanged`、`navigation.canGoBack` 或 `file.imageDropped` 后，宿主壳必须把对应 WebView 事件脚本注册或发射失败显式失败或记录日志；启动阶段无法安装网络 / 返回栈事件时不得继续以半可用状态运行，页面重放、窗口生命周期事件和拖拽图片事件阶段不得静默吞掉失败。
 - `requestHostLogin()`：微信小程序跳转原生登录页；浏览器返回 `false`，由 H5 登录弹窗承接。
 - `requestHostPayment()`：微信小程序支付跳转原生支付页；其它渠道返回 `false`，继续走 H5 / Native 二维码。
 - `setHostShareTarget()`：把当前公开作品分享目标同步给宿主。