build: update production artifacts and simplify dockerfiles to use pre-built output

docker/admin.Dockerfile

@@ -1,25 +1,8 @@
-# Admin panel (static SPA served by nginx). Build context: repository root.
-#   docker build -f docker/admin.Dockerfile --build-arg SITE_URL=https://imenpishgaman.ir -t imen-admin .
-ARG NODE_IMAGE=docker.arvancloud.ir/node:24-alpine
+# Admin panel (static SPA served by nginx). Pre-built output.
+#   docker build -f docker/admin.Dockerfile -t imen-admin .
 ARG NGINX_IMAGE=docker.arvancloud.ir/nginx:alpine
 
-FROM ${NODE_IMAGE} AS build
-ARG NPM_REGISTRY=https://registry.npmjs.org/
-ENV COREPACK_NPM_REGISTRY=${NPM_REGISTRY} npm_config_registry=${NPM_REGISTRY}
-# website address for the "view site" links
-ARG SITE_URL=https://imenpishgaman.ir
-ENV VITE_SITE_URL=${SITE_URL}
-RUN corepack enable
-WORKDIR /repo
-COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
-COPY packages/shared packages/shared
-COPY apps/admin apps/admin
-RUN pnpm config set fetch-retries 5 \
- && pnpm config set fetch-retry-maxtimeout 120000 \
- && pnpm install --frozen-lockfile --filter "@imen/admin..." || pnpm install --no-frozen-lockfile --filter "@imen/admin..."
-RUN pnpm --filter "@imen/admin..." build
-
 FROM ${NGINX_IMAGE}
 COPY docker/nginx/admin.conf /etc/nginx/conf.d/default.conf
-COPY --from=build /repo/apps/admin/dist /usr/share/nginx/html
+COPY apps/admin/dist /usr/share/nginx/html
 EXPOSE 80