feat: expand AI workflow support and refresh docs

Server/.env.example

@@ -0,0 +1,40 @@
+ENV=development
+PROJECT_NAME=DesignerCEP
+API_V1_STR=/api/v1
+DATABASE_URL=sqlite:///./designercep.db
+SECRET_KEY=replace-with-a-long-random-secret
+ACCESS_TOKEN_EXPIRE_MINUTES=10080
+ALLOWED_ORIGINS=*
+ADMIN_TOKEN=replace-with-admin-token
+
+# SMTP
+SMTP_HOST=smtp.gmail.com
+SMTP_PORT=587
+SMTP_USER=
+SMTP_PASSWORD=
+EMAILS_FROM_EMAIL=
+EMAILS_FROM_NAME=Designer
+
+# 七牛云对象存储
+QINIU_ACCESS_KEY=
+QINIU_SECRET_KEY=
+QINIU_BUCKET=
+QINIU_DOMAIN=http://image.xinhui.cloud
+
+# AI（推荐统一使用 AI_*）
+AI_PROVIDER=ark
+AI_API_KEY=
+AI_BASE_URL=https://ark.cn-beijing.volces.com/api/v3
+AI_CHAT_BASE_URL=
+AI_VISION_BASE_URL=
+AI_IMAGE_BASE_URL=
+AI_MODEL=doubao-seed-2-0-mini-260215
+AI_VISION_MODEL=doubao-seed-2-0-mini-260215
+AI_IMAGE_EDIT_MODEL=doubao-seedream-5-0-260128
+AI_CHAT_MODELS=doubao-seed-2-0-mini-260215
+AI_VISION_MODELS=doubao-seed-2-0-mini-260215
+AI_IMAGE_EDIT_MODELS=doubao-seedream-5-0-260128
+
+# 兼容旧字段
+ARK_API_KEY=
+ARK_BASE_URL=https://ark.cn-beijing.volces.com/api/v3