chore: 完善开源项目文档与结构，移除敏感原始图片

- 重写 README.md，添加在线体验、API 文档、部署指南、技术栈等
- 添加 MIT LICENSE
- 添加 CONTRIBUTING.md 贡献指南
- 添加 GitHub Issue/PR 模板
- 完善 .gitignore，防止原始图片和敏感文件误提交
- 从 git 中移除 25 个原始图片文件（.png/.jpg/非序号 webp）
- 项目结构迁移：functions/ -> src/，根目录静态文件 -> public/
- 添加 wrangler.toml 与 package.json 配置

.gitignore

@@ -1,4 +1,68 @@
+# Dependencies
+node_modules/
+package-lock.json
+
+# Build artifacts
 .build-venv/
 .wrangler/
 __pycache__/
 *.pyc
+
+# Logs
+*.log
+npm-debug.log*
+
+# Source images (only numbered .webp should be tracked; original images stay local)
+# Ignore everything in source dirs
+/mobile-image/*
+/desketop-image/*
+
+# Keep .gitkeep to preserve empty directories
+!/mobile-image/.gitkeep
+!/desketop-image/.gitkeep
+
+# Keep only purely numbered .webp in source dirs (generated build artifacts)
+# e.g. 1.webp, 10.webp, 123.webp — but NOT 3yfvfgrD.webp
+!/mobile-image/[0-9].webp
+!/mobile-image/[0-9][0-9].webp
+!/mobile-image/[0-9][0-9][0-9].webp
+!/mobile-image/[0-9][0-9][0-9][0-9].webp
+
+!/desketop-image/[0-9].webp
+!/desketop-image/[0-9][0-9].webp
+!/desketop-image/[0-9][0-9][0-9].webp
+!/desketop-image/[0-9][0-9][0-9][0-9].webp
+
+# Ignore all original image formats (redundant safety net)
+/mobile-image/*.jpg
+/mobile-image/*.jpeg
+/mobile-image/*.png
+/mobile-image/*.gif
+/mobile-image/*.bmp
+/mobile-image/*.tif
+/mobile-image/*.tiff
+
+/desketop-image/*.jpg
+/desketop-image/*.jpeg
+/desketop-image/*.png
+/desketop-image/*.gif
+/desketop-image/*.bmp
+/desketop-image/*.tif
+/desketop-image/*.tiff
+
+# OS files
+.DS_Store
+Thumbs.db
+desktop.ini
+
+# Editor / IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Wrangler local state
+.dev.vars
+.env
+.env.local