Add PDF search feature and update Docker configuration

backend.dockerfile

@@ -1,17 +1,22 @@
-FROM node:18-slim
-
+FROM node:18-slim as base
 WORKDIR /home/perplexica
+RUN mkdir -p /home/perplexica/data /home/perplexica/uploads
 
+# Development stage
+FROM base as development
+ENV NODE_ENV=development
+COPY package.json yarn.lock ./
+RUN yarn install --frozen-lockfile --network-timeout 600000
+EXPOSE 3001
+CMD ["yarn", "dev"]
+
+# Production stage
+FROM base as production
 COPY src /home/perplexica/src
 COPY tsconfig.json /home/perplexica/
 COPY drizzle.config.ts /home/perplexica/
 COPY package.json /home/perplexica/
 COPY yarn.lock /home/perplexica/
-
-RUN mkdir /home/perplexica/data
-RUN mkdir /home/perplexica/uploads
-
 RUN yarn install --frozen-lockfile --network-timeout 600000
 RUN yarn build
-
 CMD ["yarn", "start"]