updated docker file

Dockerfile

@@ -0,0 +1,25 @@
+# Flutter web build, served as static files by nginx.
+#
+# Dokploy builds this repo with its Dockerfile provider, so the image does the
+# whole job: pull the Flutter SDK, compile the web bundle, hand the output to a
+# web server. Nothing from the build stage survives into the final image but
+# build/web.
+
+FROM ghcr.io/cirruslabs/flutter:stable AS build
+
+WORKDIR /app
+
+# Dependencies resolve from the pubspec alone, so copying it first keeps the
+# `pub get` layer cached across source-only changes.
+COPY pubspec.yaml pubspec.lock ./
+RUN flutter pub get
+
+COPY . .
+RUN flutter build web --release
+
+FROM nginx:alpine
+
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+COPY --from=build /app/build/web /usr/share/nginx/html
+
+EXPOSE 80