收紧导入结果消费边界

将文本、文档、图片和音频导入结果归一化提升到共享 HostBridge 契约
让 H5 facade 消费宿主导入结果前复核文件名、MIME、字节数和 base64 载荷
移除 H5 facade 本地导入 MIME Set 并用总门禁反查共享 normalizer
增加导入结果边界测试和超限结果回退覆盖
同步宿主壳协议文档和共享决策记录

scripts/check-native-shells.mjs

@@ -972,10 +972,6 @@ function assertH5HostBridgePayloadBoundaries() {
   );
 
   for (const sharedBoundary of [
-    'HOST_BRIDGE_TEXT_MIME_TYPES',
-    'HOST_BRIDGE_DOCUMENT_MIME_TYPES',
-    'HOST_BRIDGE_IMAGE_MIME_TYPES',
-    'HOST_BRIDGE_AUDIO_MIME_TYPES',
     'HOST_BRIDGE_RUNTIME_REFRESH_TIMEOUT_MS',
     'HOST_BRIDGE_USER_INTERACTION_TIMEOUT_MS',
     'HOST_BRIDGE_SCANNER_TIMEOUT_MS',
@@ -1132,6 +1128,54 @@ function assertH5HostBridgePayloadBoundaries() {
       'H5 HostBridge facade must normalize app.setTitle payloads with the shared title boundary',
     );
   }
+  for (const importBoundary of [
+    {
+      functionName: 'importHostTextFile',
+      normalizer: 'normalizeHostBridgeImportTextResult',
+    },
+    {
+      functionName: 'importHostDocumentFile',
+      normalizer: 'normalizeHostBridgeImportDocumentResult',
+    },
+    {
+      functionName: 'importHostImageFile',
+      normalizer: 'normalizeHostBridgeImportImageResult',
+    },
+    {
+      functionName: 'captureHostImageFile',
+      normalizer: 'normalizeHostBridgeImportImageResult',
+    },
+    {
+      functionName: 'importHostAudioFile',
+      normalizer: 'normalizeHostBridgeImportAudioResult',
+    },
+    {
+      functionName: 'subscribeHostImageDrop',
+      normalizer: 'normalizeHostBridgeImportImageResult',
+    },
+  ]) {
+    const functionSource = extractFunctionSource(
+      h5HostBridgeSource,
+      importBoundary.functionName,
+    );
+    if (!functionSource.includes(`${importBoundary.normalizer}(`)) {
+      throw new Error(
+        `${importBoundary.functionName} must normalize imported file results with shared ${importBoundary.normalizer}`,
+      );
+    }
+  }
+  for (const localMimeSet of [
+    'HOST_BRIDGE_TEXT_MIME_TYPE_SET',
+    'HOST_BRIDGE_DOCUMENT_MIME_TYPE_SET',
+    'HOST_BRIDGE_IMAGE_MIME_TYPE_SET',
+    'HOST_BRIDGE_AUDIO_MIME_TYPE_SET',
+  ]) {
+    if (h5HostBridgeSource.includes(localMimeSet)) {
+      throw new Error(
+        `H5 HostBridge facade must use shared import normalizers instead of local ${localMimeSet}`,
+      );
+    }
+  }
 }
 
 function assertH5NativeAppTransportTimeoutBoundaries() {