Add Docker deployment support for Dokploy

- Add Dockerfile with multi-stage build
- Add docker-compose.yml with Traefik labels
- Add .dockerignore for optimal build context
- Update next.config.ts for standalone output
- Update DEPLOYMENT.md with Dokploy instructions

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

.dockerignore

@@ -0,0 +1,51 @@
+# Dependencies
+node_modules
+npm-debug.log
+yarn-error.log
+
+# Next.js
+.next
+out
+
+# Testing
+coverage
+.nyc_output
+
+# Misc
+.DS_Store
+*.pem
+
+# Debug
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Local env files
+.env
+.env*.local
+.env.production
+
+# Vercel
+.vercel
+
+# TypeScript
+*.tsbuildinfo
+next-env.d.ts
+
+# Git
+.git
+.gitignore
+
+# Docker
+Dockerfile
+docker-compose.yml
+.dockerignore
+
+# Documentation
+README.md
+DEPLOYMENT.md
+
+# BMAD (development only)
+_bmad
+_agent
+.claude