feat: enhance login modal and avatar selection process

- Updated the login modal to include a user agreement section with clickable links to the user agreement and privacy policy.
- Improved button styling and layout for better user experience.
- Refactored avatar selection process to utilize local image paths, enhancing compatibility and reliability across different environments.
- Added utility functions for resolving avatar file paths and selecting images from the gallery or camera.

This update aims to streamline user interactions during login and avatar selection, ensuring a smoother experience.

reactH5/.env.development.example

@@ -0,0 +1,16 @@
+# reactH5 本地开发 · 对接 soul-api
+# 复制为 .env.development 后按需修改（.env.development 可加入本地 .gitignore）
+
+# ---------- 模式 A（推荐）：浏览器请求相对路径 /api，由 Vite 转发到 soul-api ----------
+# 留空则 fetch 走当前 dev 源（如 http://localhost:5173/api/...），依赖下方代理
+VITE_API_BASE_URL=
+
+# 代理目标：vite.config 默认已是 http://127.0.0.1:9100；仅连线上时取消注释下一行
+# VITE_PROXY_TARGET=https://soulapi.quwanzhi.com
+
+# ---------- 若 h5/login-by-phone 仍 403 ----------
+# 说明代理到的 soul-api 在 release 且未开 H5：线上须 H5_PHONE_LOGIN_ENABLED=1；本地须 GIN_MODE=debug 等（见接口返回 error 全文）。
+
+# ---------- 模式 B：浏览器直连 soul-api（需 soul-api CORS 含 H5 源，默认已含 localhost:5173）----------
+# VITE_API_BASE_URL=http://127.0.0.1:9100
+# 直连时 VITE_PROXY_TARGET 不参与浏览器请求，可保留或删除