build(deploy): 部署配置 - 转发 CANVAS_PUBLIC_BASE_URL (#564)

Original-Commit: 1734438cd00963a607795b2a6640ab7827e487e0
build(deploy): 部署配置 - 转发 CANVAS_PUBLIC_BASE_URL

后端读 CANVAS_PUBLIC_BASE_URL（resource.go 用它拼本地存储的短时签名链接，取不到时的报错
也在提示管理员配置它），但 5 个 Compose 文件都没有把它传进容器：按报错操作的管理员把变量
写进 .env 之后没有任何效果，而报错文案仍在让他"去配置"。

5 个编排与 .env.example 一并补齐（默认空值，行为与现状一致），并说明内网部署还需把该主机
放进 CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS。无代码改动。

.env.example

@@ -5,6 +5,9 @@ CANVAS_ALLOW_PRIVATE_UPSTREAMS=false
 # 多个主机使用英文逗号分隔，例如：gateway.internal,192.168.1.10
 CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS=
 CANVAS_CORS_ORIGINS=http://localhost:3000
+# 服务器对模型上游可访问的地址：本地存储的短时签名链接（Agent 看图、生成任务参考图）由它拼出，
+# 内网部署还要把该主机放进 CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS。留空则本地存储无法签出链接。
+CANVAS_PUBLIC_BASE_URL=
 # 启用服务商插件系统以支持特定服务的模型发现（如阿里云百炼的视频生成模型）
 # 设置为 true 启用插件机制，false 使用传统方式（默认：false）
 ENABLE_PROVIDER_PLUGINS=false

docker-compose.deploy.yml

@@ -53,6 +53,7 @@ services:
       CANVAS_ALLOW_PRIVATE_UPSTREAMS: ${CANVAS_ALLOW_PRIVATE_UPSTREAMS:-false}
       CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS: ${CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS:-}
       CANVAS_CORS_ORIGINS: ${CANVAS_CORS_ORIGINS:-}
+      CANVAS_PUBLIC_BASE_URL: ${CANVAS_PUBLIC_BASE_URL:-}
       CANVAS_UPDATER_SOCKET: /run/open-ai-canvas-updater/updater.sock
       CANVAS_UPDATER_TOKEN: ${CANVAS_UPDATER_TOKEN:-}
       GIN_MODE: release

docker-compose.dev.yml

@@ -26,6 +26,8 @@ services:
       CANVAS_ALLOW_PRIVATE_UPSTREAMS: ${CANVAS_ALLOW_PRIVATE_UPSTREAMS:-false}
       CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS: ${CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS:-}
       CANVAS_CORS_ORIGINS: ${CANVAS_CORS_ORIGINS:-http://localhost:3000}
+      # 服务器访问地址：Agent 看图与生成参考图都靠它签发上游可取到的短时链接。
+      CANVAS_PUBLIC_BASE_URL: ${CANVAS_PUBLIC_BASE_URL:-}
       GIN_MODE: debug
     volumes:
       - type: bind

docker-compose.local.yml

@@ -19,6 +19,8 @@ services:
       CANVAS_ALLOW_PRIVATE_UPSTREAMS: ${CANVAS_ALLOW_PRIVATE_UPSTREAMS:-false}
       CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS: ${CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS:-}
       CANVAS_CORS_ORIGINS: ${CANVAS_CORS_ORIGINS:-http://localhost:3000}
+      # 服务器访问地址：Agent 看图与生成参考图都靠它签发上游可取到的短时链接。
+      CANVAS_PUBLIC_BASE_URL: ${CANVAS_PUBLIC_BASE_URL:-}
       ENABLE_PROVIDER_PLUGINS: ${ENABLE_PROVIDER_PLUGINS:-false}
       GIN_MODE: release
     volumes:

docker-compose.server.yml

@@ -67,6 +67,7 @@ services:
       CANVAS_ALLOW_PRIVATE_UPSTREAMS: ${CANVAS_ALLOW_PRIVATE_UPSTREAMS:-false}
       CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS: ${CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS:-}
       CANVAS_CORS_ORIGINS: ${CANVAS_CORS_ORIGINS:-*}
+      CANVAS_PUBLIC_BASE_URL: ${CANVAS_PUBLIC_BASE_URL:-}
       GIN_MODE: release
     volumes:
       - ${CANVAS_DATA_PATH:-./data}:/data

docker-compose.yml

@@ -19,6 +19,8 @@ services:
       CANVAS_ALLOW_PRIVATE_UPSTREAMS: ${CANVAS_ALLOW_PRIVATE_UPSTREAMS:-false}
       CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS: ${CANVAS_ALLOWED_PRIVATE_UPSTREAM_HOSTS:-}
       CANVAS_CORS_ORIGINS: ${CANVAS_CORS_ORIGINS:-http://localhost:3000}
+      # 服务器访问地址：Agent 看图与生成参考图都靠它签发上游可取到的短时链接。
+      CANVAS_PUBLIC_BASE_URL: ${CANVAS_PUBLIC_BASE_URL:-}
       GIN_MODE: release
     volumes:
       - backend-data:/data