Custom Command Enhancements

• Frontmatter parsing: Custom commands now support YAML-style frontmatter in markdown files

  title: My Command
  description: Does something useful
  
  Command content here...

• Inline bash execution: Execute bash commands directly within custom command markdown
• Block syntax: `!echo "Hello from command"`
• Inline syntax: ` !date `
• Commands are validated and executed with proper permissions
• Output is inserted directly into the rendered content