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

public/manifest.json

@@ -0,0 +1,42 @@
+{
+  "generated_at": "2026-05-18T11:45:45.514521+00:00",
+  "variants": {
+    "mobile": {
+      "folder": "mobile-image",
+      "count": 6,
+      "images": [
+        "1.webp",
+        "2.webp",
+        "3.webp",
+        "4.webp",
+        "5.webp",
+        "6.webp"
+      ]
+    },
+    "desktop": {
+      "folder": "desketop-image",
+      "count": 19,
+      "images": [
+        "1.webp",
+        "2.webp",
+        "3.webp",
+        "4.webp",
+        "5.webp",
+        "6.webp",
+        "7.webp",
+        "8.webp",
+        "9.webp",
+        "10.webp",
+        "11.webp",
+        "12.webp",
+        "13.webp",
+        "14.webp",
+        "15.webp",
+        "16.webp",
+        "17.webp",
+        "18.webp",
+        "19.webp"
+      ]
+    }
+  }
+}