build: 优化 Docker/Workflow 构建，使用 Next.js 环境变量注入版本和构建时间，并移除对 package.json 的硬编码替换

.github/workflows/build-image.yml

@@ -59,6 +59,7 @@ jobs:
           fi
 
           echo "VERSION=$VERSION" >> "$GITHUB_ENV"
+          echo "BUILD_DATE=$(date -u +'%Y-%m-%d %H:%M:%S')" >> "$GITHUB_ENV"
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v4
@@ -80,6 +81,7 @@ jobs:
           outputs: type=image,name=${{ env.IMAGE }},push-by-digest=true,name-canonical=true,push=true
           build-args: |
             VERSION=${{ env.VERSION }}
+            BUILD_DATE=${{ env.BUILD_DATE }}
           cache-from: type=gha,scope=docker-server-${{ matrix.arch }}
           cache-to: type=gha,mode=max,ignore-error=true,timeout=20m,scope=docker-server-${{ matrix.arch }}