feat #支持 url json导入

[gaoconggit]

扩展现有的json导入功能，在支持上传本地json文件的基础上，扩展支持在线 json,如 github rawcontent

[gaoconggit]

@claude 实现这个功能

[claude]

Claude finished @gaoconggit's task —— View job • claude/issue-69-20251027-1531 • Create PR ➔

---

Implementing URL JSON Import Feature ✅

I've successfully implemented URL JSON import support for the folder import feature!

Task List

• Read project guidelines (CLAUDE.md)
• Explore current JSON import implementation
• Design the enhancement (UI + backend)
• Implement frontend UI changes (add URL input option)
• Add error handling and validation
• Test the implementation (build successful)
• Commit and push changes
• Provide PR creation link

Implementation Summary

Modified File: SharpPad/wwwroot/fileSystem/fileManager.js

New Features:

1. Two-way Import Selection - When users click "导入" (Import) in the folder context menu, they now see a modal dialog with two options:

   • 📁 从本地文件导入 (Import from local file)
   • 🌐 从 URL 导入 (Import from URL)

2. URL Import Support - The new URL import feature includes:

   • URL input prompt with validation
   • Support for any publicly accessible JSON URL (including GitHub raw content)
   • Automatic content fetching using the Fetch API
   • Content-type validation with warnings for non-JSON files
   • Comprehensive error handling for network failures and CORS issues
   • User-friendly error messages in Chinese

3. Code Organization - Refactored the original file import logic into separate methods:

   • selectImportMethod() - Shows the selection dialog
   • importFromUrl() - Handles URL-based imports
   • importFromFile() - Handles local file uploads (original functionality)

Key Benefits:

• ✅ Supports GitHub raw content URLs (e.g., https://raw.githubusercontent.com/...)
• ✅ Works with any publicly accessible JSON URL
• ✅ No backend changes required (pure frontend implementation)
• ✅ Maintains 100% backward compatibility with existing file upload
• ✅ Simple and intuitive user interface
• ✅ Robust error handling and validation

Testing:

• ✅ Build successful with no new errors or warnings
• ✅ Code follows project guidelines (simplicity, readability, minimal changes)

Example Usage

Users can now import folders from URLs like:

• GitHub raw content: https://raw.githubusercontent.com/user/repo/main/folder.json
• Any public JSON file: https://example.com/data/folder.json

--- • Branch: claude/issue-69-20251027-1531