feat(ci): improve Docker workflow with Buildx, caching and semver tags

- Add Docker Buildx for multi-arch support
- Enable GitHub Actions cache for faster builds
- Add semver tagging for version releases (v*)
- Build on PRs without pushing (validation only)
- Add conditional push based on event type

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: devZenta

.github/workflows/docker.yml

@@ -1,26 +1,35 @@
-name: Docker
+name: Build and Publish Docker Image
 
 on:
   push:
-    branches: [main]
+    branches:
+      - main
+    tags:
+      - "v*"
+  pull_request:
+    branches:
+      - main
 
 env:
   REGISTRY: ghcr.io
   IMAGE_NAME: ${{ github.repository }}
 
 jobs:
   build-and-push:
-    name: Build & Push Docker Image
     runs-on: ubuntu-latest
     permissions:
       contents: read
       packages: write
 
     steps:
-      - name: Checkout code
+      - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Log in to Container Registry
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: ${{ env.REGISTRY }}
@@ -33,13 +42,18 @@ jobs:
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           tags: |
-            type=raw,value=latest
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
             type=sha,prefix=
 
       - name: Build and push Docker image
         uses: docker/build-push-action@v6
         with:
           context: .
-          push: true
+          push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max