CLI tool for scaffolding

[RAprogramm]

Problem

No quick start experience. User must:

• Add dependencies manually
• Write entity struct from scratch
• Remember attribute syntax
• Set up features correctly

Why it matters

• First impression matters for adoption
• 30-second demo effect
• Reduces learning curve
• Generates correct boilerplate

Acceptance criteria

• cargo install entity-cli
• entity init - setup project
• entity new <Name> - scaffold entity
• Generate valid, working code
• No wizard/interactive prompts