fix: Separate Docker workflows for testing and publishing

- Add docker-test.yml for PR validation (build test only)
- Fix build_and_publish_docker.yml to trigger only on tags
- Remove problematic sha prefix causing invalid tag format
- Ensure proper workflow sequence: PR test → merge → version → publish

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/build_and_publish_docker.yml

@@ -2,10 +2,7 @@ name: Build and Publish Docker Image to GHCR
 
 on:
   push:
-    branches: [ main ]
     tags: [ 'v*' ]
-  pull_request:
-    branches: [ main ]
 
 env:
   REGISTRY: ghcr.io
@@ -27,7 +24,6 @@ jobs:
       uses: docker/setup-buildx-action@v3
 
     - name: Log in to GitHub Container Registry
-      if: github.event_name != 'pull_request'
       uses: docker/login-action@v3
       with:
         registry: ${{ env.REGISTRY }}
@@ -40,25 +36,10 @@ jobs:
       with:
         images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
         tags: |
-          type=ref,event=branch
-          type=ref,event=pr
           type=ref,event=tag
-          type=sha,prefix={{branch}}-
           type=raw,value=latest,enable={{is_default_branch}}
 
-    - name: Build Docker image for PR
-      if: github.event_name == 'pull_request'
-      uses: docker/build-push-action@v5
-      with:
-        context: .
-        push: false
-        tags: ${{ steps.meta.outputs.tags }}
-        labels: ${{ steps.meta.outputs.labels }}
-        cache-from: type=gha
-        cache-to: type=gha,mode=max
-
     - name: Build and push Docker image
-      if: github.event_name != 'pull_request'
       uses: docker/build-push-action@v5
       with:
         context: .
@@ -69,7 +50,6 @@ jobs:
         cache-to: type=gha,mode=max
 
     - name: Generate artifact attestation
-      if: github.event_name != 'pull_request'
       uses: actions/attest-build-provenance@v1
       with:
         subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME}}

.github/workflows/docker-test.yml

@@ -0,0 +1,31 @@
+name: Docker Build Test
+
+on:
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  docker-build-test:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
+
+    - name: Test Docker build
+      uses: docker/build-push-action@v5
+      with:
+        context: .
+        push: false
+        tags: test:latest
+        cache-from: type=gha
+        cache-to: type=gha,mode=max
+
+    - name: Build test summary
+      run: |
+        echo "### ✅ Docker Build Test Passed" >> $GITHUB_STEP_SUMMARY
+        echo "" >> $GITHUB_STEP_SUMMARY
+        echo "Docker image builds successfully and is ready for production." >> $GITHUB_STEP_SUMMARY