接入桌面壳文本文件导出能力

新增 HostBridge file.exportText 契约、文件名清洗和 H5 导出入口

Tauri 桌面壳通过受控 host_bridge_request 打开保存对话框并写入文本文件

Expo 移动壳对未接入的文件导出能力明确返回 unsupported

更新宿主壳方案、统一协议和项目共享决策记录

packages/shared/src/contracts/hostBridge.test.ts

@@ -1,6 +1,9 @@
 import { describe, expect, test } from 'vitest';
 
-import { normalizeHostBridgeExternalUrl } from './hostBridge';
+import {
+  normalizeHostBridgeExportFileName,
+  normalizeHostBridgeExternalUrl,
+} from './hostBridge';
 
 describe('HostBridge shared contract helpers', () => {
   test('只允许明确的外链协议交给宿主打开', () => {
@@ -24,4 +27,19 @@ describe('HostBridge shared contract helpers', () => {
     ).toBeNull();
     expect(normalizeHostBridgeExternalUrl('/relative/path')).toBeNull();
   });
+
+  test('归一化宿主导出文件名', () => {
+    expect(normalizeHostBridgeExportFileName('  作品:记录?.txt  ')).toBe(
+      '作品-记录-.txt',
+    );
+    expect(normalizeHostBridgeExportFileName('../secret.txt')).toBe(
+      'secret.txt',
+    );
+    expect(normalizeHostBridgeExportFileName('')).toBe(
+      'genarrative-export.txt',
+    );
+    expect(normalizeHostBridgeExportFileName('a'.repeat(140))).toHaveLength(
+      120,
+    );
+  });
 });

packages/shared/src/contracts/hostBridge.ts

@@ -23,6 +23,7 @@ export type HostBridgeMethod =
   | 'app.openExternalUrl'
   | 'app.setTitle'
   | 'clipboard.writeText'
+  | 'file.exportText'
   | 'haptics.impact';
 
 export type HostBridgeCapability =
@@ -143,6 +144,18 @@ export type ClipboardWriteTextPayload = {
   text: string;
 };
 
+export type FileExportTextPayload = {
+  fileName: string;
+  content: string;
+  mimeType?: string;
+};
+
+export type FileExportTextResult = {
+  action: 'saved';
+  fileName: string;
+  bytes: number;
+};
+
 export type HapticsImpactPayload = {
   style?: 'light' | 'medium' | 'heavy';
 };
@@ -156,3 +169,34 @@ export type ShareOpenPayload = {
   message?: string;
   url?: string;
 };
+
+const HOST_BRIDGE_FILE_NAME_FALLBACK = 'genarrative-export.txt';
+const HOST_BRIDGE_FILE_NAME_MAX_LENGTH = 120;
+
+function isHostBridgeInvalidFileNameCharacter(value: string) {
+  if (hasHostBridgeControlCharacter(value)) {
+    return true;
+  }
+
+  return ['<', '>', ':', '"', '/', '\\', '|', '?', '*'].includes(value);
+}
+
+export function normalizeHostBridgeExportFileName(rawFileName: unknown) {
+  if (typeof rawFileName !== 'string') {
+    return HOST_BRIDGE_FILE_NAME_FALLBACK;
+  }
+
+  const fileName = rawFileName
+    .trim()
+    .split('')
+    .map((character) =>
+      isHostBridgeInvalidFileNameCharacter(character) ? '-' : character,
+    )
+    .join('')
+    .replace(/\s+/g, ' ')
+    .replace(/^[.\s-]+/, '')
+    .slice(0, HOST_BRIDGE_FILE_NAME_MAX_LENGTH)
+    .trim();
+
+  return fileName || HOST_BRIDGE_FILE_NAME_FALLBACK;
+}