chore: Optimize Dockerfile for improved build performance and update Gitea workflows with Docker Buildx support

.dockerignore

@@ -0,0 +1,69 @@
+# Dependencies
+node_modules
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Production builds
+frontend/dist
+frontend/build
+
+# Environment files
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# IDE files
+.vscode
+.idea
+*.swp
+*.swo
+
+# OS files
+.DS_Store
+Thumbs.db
+
+# Git
+.git
+.gitignore
+
+# Documentation
+README.md
+CHANGELOG.md
+DOCKER.md
+
+# CI/CD
+.gitea
+
+# Logs
+logs
+*.log
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# Dependency directories
+jspm_packages/
+
+# Optional npm cache directory
+.npm
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity