feat: add Railway deployment support with CI/CD integration

- Add Railway-specific Docker image build to CI/CD workflow
  - Builds n8n-mcp-railway image alongside standard image
  - Railway image optimized for AMD64 architecture
  - Automatically published to ghcr.io on main branch pushes

- Create comprehensive Railway deployment documentation
  - Step-by-step deployment guide with security best practices
  - Claude Desktop connection instructions via mcp-remote
  - Troubleshooting guide for common issues
  - Architecture details and single-instance design explanation

- Update README with Railway documentation link
  - Removed inline Railway content to keep README focused
  - Added link to dedicated Railway deployment guide

This enables zero-configuration cloud deployment of n8n-mcp
with automatic HTTPS, global access, and built-in monitoring.

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

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

.github/workflows/docker-build.yml

@@ -70,6 +70,60 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           provenance: false
 
+  build-railway:
+    name: Build Railway Docker Image
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          lfs: true
+        
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+        
+      - name: Set up Docker Buildx
+        id: buildx
+        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 }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+          
+      - name: Extract metadata for Railway
+        id: meta-railway
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}-railway
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=sha,prefix={{branch}}-,format=short
+            type=raw,value=latest,enable={{is_default_branch}}
+            
+      - name: Build and push Railway Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile.railway
+          no-cache: true
+          platforms: linux/amd64
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta-railway.outputs.tags }}
+          labels: ${{ steps.meta-railway.outputs.labels }}
+          provenance: false
+
   # Nginx build commented out until Phase 2
   # build-nginx:
   #   name: Build nginx-enhanced Docker Image