chore: squash merge customizations from develop-old-0.1.77

- 定制文档: CLAUDE.md, AGENTS.md
- UI定制: 微信客服按钮, 首页改造, 移除GitHub链接
- 部署运维: docker-compose.yml, 压测脚本
- CI/gitignore 小改动

.github/workflows/backend-ci.yml

@@ -17,6 +17,7 @@ jobs:
           go-version-file: backend/go.mod
           check-latest: false
           cache: true
+          cache-dependency-path: backend/go.sum
       - name: Verify Go version
         run: |
           go version | grep -q 'go1.25.7'
@@ -36,6 +37,7 @@ jobs:
           go-version-file: backend/go.mod
           check-latest: false
           cache: true
+          cache-dependency-path: backend/go.sum
       - name: Verify Go version
         run: |
           go version | grep -q 'go1.25.7'