remove env files

Author: Junyi-99

.env.example

@@ -3,6 +3,3 @@
 
 # OpenAI API Key
 OPENAI_API_KEY=your_openai_api_key_here
-
-# Application Settings
-NODE_ENV=development

.env.prod

@@ -1,9 +1,12 @@
-name: Build Image for API
+name: Build and Push Docker Image
 
 on:
   push:
     branches:
       - main
+  pull_request:
+    branches:
+      - main
 
 jobs:
   build:
@@ -15,9 +18,6 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
-        with:
-          submodules: true
-          token: ${{ secrets.PERSONAL_ACCESS_TOKEN }}
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
@@ -33,7 +33,23 @@ jobs:
         id: sha
         run: echo "SHORT_SHA=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
 
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository_owner }}/paperdebugger-mcp-server
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=sha,prefix={{branch}}-
+
       - name: Build and push Docker image
-        run: |
-          docker build --no-cache -t ghcr.io/paperdebugger/pd-core-latex:api-${{ steps.sha.outputs.SHORT_SHA }} -f docker/api/Dockerfile .
-          docker push ghcr.io/paperdebugger/pd-core-latex:api-${{ steps.sha.outputs.SHORT_SHA }}
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./docker/Dockerfile
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max