fix: use pkg-config path for OpenCV

Dockerfile

@@ -14,14 +14,9 @@ WORKDIR /app
 # 复制源代码
 COPY . .
 
-# 设置 CGO 编译标志 - OpenCV 4 头文件路径
-ENV CGO_ENABLED=1
-ENV CGO_CFLAGS="-I/usr/include/opencv4"
-ENV CGO_LDFLAGS="-lopencv_core -lopencv_imgproc -lopencv_imgcodecs"
-
-# 构建
+# 使用 pkg-config 获取 OpenCV 编译标志
 RUN go mod download || true
-RUN go build -ldflags="-s -w" -o anticaptcha ./cmd/server
+RUN PKG_CONFIG_PATH=/usr/lib/x86_64-linux-gnu/pkgconfig CGO_ENABLED=1 go build -ldflags="-s -w" -o anticaptcha ./cmd/server
 
 # 运行阶段
 FROM debian:bookworm-slim