Fix Docker build: enable PHP gd for PhpSpreadsheet.

Composer install failed because phpspreadsheet requires ext-gd; install libpng/jpeg/freetype and compile gd.

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile

@@ -2,13 +2,17 @@ FROM php:8.2-apache
 
 ENV DEBIAN_FRONTEND=noninteractive
 
-# libsqlite3-dev 是编译 pdo_sqlite 所必需的
+# pdo_sqlite / zip / gd（PhpSpreadsheet 需要 gd）
 RUN apt-get update \
     && apt-get install -y --no-install-recommends \
         libsqlite3-dev \
         libzip-dev \
+        libpng-dev \
+        libjpeg62-turbo-dev \
+        libfreetype6-dev \
         unzip \
-    && docker-php-ext-install pdo_sqlite zip \
+    && docker-php-ext-configure gd --with-freetype --with-jpeg \
+    && docker-php-ext-install pdo_sqlite zip gd \
     && a2enmod rewrite headers \
     && rm -rf /var/lib/apt/lists/*