修复架构问题：显式指定 linux/amd64 平台

问题：
- 私有仓库缓存了 ARM64 镜像（从 Mac M1/M2/M3 推送）
- 服务器是 AMD64 架构，导致 exec format error

解决：
- 在所有 FROM 指令中添加 --platform=linux/amd64
- 强制使用 AMD64 镜像，避免架构不匹配
- 适用于 Dockerfile.api 和 Dockerfile.worker

Dockerfile.api

@@ -1,7 +1,7 @@
 # ================================
 # 阶段 1: 构建阶段
 # ================================
-FROM registry.boss160.cn/base/golang:1.25.6-alpine AS builder
+FROM --platform=linux/amd64 registry.boss160.cn/base/golang:1.25.6-alpine AS builder
 
 # 使用阿里云镜像源加速
 RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories
@@ -37,7 +37,7 @@ RUN go install -tags 'postgres' github.com/golang-migrate/migrate/v4/cmd/migrate
 # ================================
 # 阶段 2: 运行阶段
 # ================================
-FROM registry.boss160.cn/base/alpine:3.19
+FROM --platform=linux/amd64 registry.boss160.cn/base/alpine:3.19
 
 # 使用阿里云镜像源加速
 RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories

Dockerfile.worker

@@ -1,7 +1,7 @@
 # ================================
 # 阶段 1: 构建阶段
 # ================================
-FROM registry.boss160.cn/base/golang:1.25.6-alpine AS builder
+FROM --platform=linux/amd64 registry.boss160.cn/base/golang:1.25.6-alpine AS builder
 
 # 使用阿里云镜像源加速
 RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories
@@ -34,7 +34,7 @@ RUN GOOS=linux GOARCH=amd64 go build \
 # ================================
 # 阶段 2: 运行阶段
 # ================================
-FROM registry.boss160.cn/base/alpine:3.19
+FROM --platform=linux/amd64 registry.boss160.cn/base/alpine:3.19
 
 # 使用阿里云镜像源加速
 RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories