fix: add .dockerignore to ensure proper Docker build context

The Docker build was failing because Docker was using .gitignore patterns
to filter the build context, which excluded the cmd/ directory.

This new .dockerignore file explicitly controls what gets copied into
the Docker build context, ensuring all source files are included while
excluding build artifacts and cache files.

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

.dockerignore

@@ -0,0 +1,19 @@
+# Build outputs
+dist/
+
+# Dependency directories
+vendor/
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Aider cache
+.aider*