imporve dockerfie form layer caching

Dockerfile

@@ -1,7 +1,14 @@
-FROM oven/bun:1 as install
+FROM oven/bun:1 as base
+
+FROM base as install
 RUN mkdir -p /temp/prod
-COPY . /temp/prod
-RUN cd /temp/prod && bun install --production --frozen-lockfile && bun run build
+COPY package.json bun.lockb /temp/prod/
+RUN cd /temp/prod && bun install --production --frozen-lockfile
+
+FROM base as build
+RUN mkdir -p /temp/prod
+COPY . /temp/prod/
+RUN cd /temp/prod && bun run build
 
 FROM nginx AS release
-COPY --from=install /temp/prod/dist /usr/share/nginx/html
+COPY --from=build /temp/prod/dist /usr/share/nginx/html

bunfig.toml

@@ -1,2 +1,7 @@
 [test]
 preload = './happydom.ts'
+
+[install.lockfile]
+# whether to save a non-Bun lockfile alongside bun.lockb
+# only "yarn" is supported
+print = "yarn"