fix(docker): 优化 Dockerfile.base 减少构建阶段复杂度

- 合并构建和运行环境，移除多阶段构建
- 统一设置环境变量，优化时区配置为 Asia/Shanghai
- 替换 Alpine 镜像源为阿里云镜像提升下载速度
- 在运行环境安装所有必需依赖（含 git、curl、tzdata）
- 保证 Go 依赖下载并校验完整性，提升构建可靠性
- 删除冗余注释和步骤，简化 Dockerfile 结构

kami-gateway/Dockerfile.base

@@ -1,47 +1,28 @@
 # Base Image for kami-gateway applications
 # Contains Go 1.25 build environment and Alpine runtime
 
-FROM golang:1.25-alpine AS builder
+FROM golang:1.25-alpine
 
-# Set environment variables for building
-ENV GO111MODULE=on \
+# Set environment variables
+ENV TZ=Asia/Shanghai \
+    GO111MODULE=on \
     GOPROXY=https://goproxy.cn,direct \
     CGO_ENABLED=0 \
     GOOS=linux \
     GOARCH=amd64
 
-# Install build dependencies
-RUN apk add --no-cache \
-    git \
-    ca-certificates \
-    tzdata
-
-# Create application directory
-WORKDIR /build
-
-# Copy Go modules files for caching
-COPY go.mod go.sum* ./
-
-# Download dependencies (this layer will be cached unless go.mod changes)
-RUN go mod download && go mod verify
-
-# Create runtime stage
-FROM alpine:latest
-
-# Set environment variables
-ENV TZ=Asia/Shanghai
-
 # Set up Alpine repositories (use China mirror for faster downloads)
 RUN echo "https://mirrors.aliyun.com/alpine/v3.22/main/" > /etc/apk/repositories && \
     echo "https://mirrors.aliyun.com/alpine/v3.22/community/" >> /etc/apk/repositories
 
-# Install runtime dependencies
+# Install all dependencies
 RUN apk update && \
     apk upgrade && \
     apk add --no-cache \
         tzdata \
         curl \
-        ca-certificates && \
+        ca-certificates \
+        git && \
     # Set timezone
     cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime && \
     echo "Asia/Shanghai" > /etc/timezone && \
@@ -74,7 +55,7 @@ WORKDIR /app
 COPY --chown=appuser:appuser go.mod go.sum* ./
 
 # Pre-download Go dependencies for faster builds
-RUN go mod download
+RUN go mod download && go mod verify
 
 # Label the image
 LABEL maintainer="kami-gateway-team" \