docs: 支付模块开发文档 + git 域名更新

- 新增 backend/design/支付模块架构概览.md
- 新增 backend/design/支付模块数据库设计.md (21张表 DDL)
- 新增 backend/design/支付模块接口设计.md
- git.dev.vifo.cc → git.vifo.cc 全局替换

gitea-runner-docker-compose.yml

@@ -6,9 +6,9 @@ services:
       - USER_UID=1000
       - USER_GID=1000
       - GITEA__database__DB_TYPE=sqlite3
-      - GITEA__server__DOMAIN=git.dev.vifo.cc
-      - GITEA__server__ROOT_URL=https://git.dev.vifo.cc
-      - GITEA__server__SSH_DOMAIN=git.dev.vifo.cc
+      - GITEA__server__DOMAIN=git.vifo.cc
+      - GITEA__server__ROOT_URL=https://git.vifo.cc
+      - GITEA__server__SSH_DOMAIN=git.vifo.cc
       - GITEA__actions__ENABLED=true
       - GITEA__webhook__ALLOWED_HOST_LIST=*
         # 或者只允许特定网段：
@@ -32,7 +32,7 @@ services:
     container_name: runner-default
     environment:
       CONFIG_FILE: /config.yaml
-      GITEA_INSTANCE_URL: "https://git.dev.vifo.cc"
+      GITEA_INSTANCE_URL: "https://git.vifo.cc"
       GITEA_RUNNER_REGISTRATION_TOKEN: "${GITEA_RUNNER_TOKEN}"
       GITEA_RUNNER_NAME: "runner-default"
       GITEA_RUNNER_LABELS: "ubuntu-latest:docker://node:20-slim"
@@ -54,7 +54,7 @@ services:
     container_name: runner-node
     environment:
       CONFIG_FILE: /config.yaml
-      GITEA_INSTANCE_URL: "https://git.dev.vifo.cc"
+      GITEA_INSTANCE_URL: "https://git.vifo.cc"
       GITEA_RUNNER_REGISTRATION_TOKEN: "${GITEA_RUNNER_TOKEN}"
       GITEA_RUNNER_NAME: "runner-node"
       GITEA_RUNNER_LABELS: "node:docker://node:20-slim,ubuntu-latest:docker://node:20-slim"
@@ -83,7 +83,7 @@ services:
     restart: always
     environment:
       CONFIG_FILE: /config.yaml
-      GITEA_INSTANCE_URL: "https://git.dev.vifo.cc"
+      GITEA_INSTANCE_URL: "https://git.vifo.cc"
       GITEA_RUNNER_REGISTRATION_TOKEN: "${GITEA_RUNNER_TOKEN}"
       GITEA_RUNNER_NAME: "runner-java"
       GITEA_RUNNER_LABELS: "java:docker://maven:3.9-eclipse-temurin-17,ubuntu-latest:docker://maven:3.9-eclipse-temurin-17"