refactor: make optimized Dockerfile the default - remove full variant

- Rename Dockerfile.optimized to Dockerfile (now the default)
- Keep old Dockerfile as Dockerfile.old for reference
- Update GitHub Actions to use default Dockerfile
- Remove build-full job - only one image variant now
- Remove docker-compose.optimized.yml and other variants
- Update all documentation to reflect single image approach

The optimized 283MB image is now the only n8n-MCP Docker image.
This simplifies the user experience and provides the best solution
for all use cases.

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

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

docker-compose.yml

@@ -3,7 +3,6 @@ version: '3.8'
 
 services:
   n8n-mcp:
-    # Use 'latest' for optimized image (~200MB) or 'full' for development (2.6GB)
     image: ghcr.io/czlonkowski/n8n-mcp:latest
     container_name: n8n-mcp
     restart: unless-stopped