[CLI] Implement generate command

[copyleftdev]

Task

Implement gen3s1s generate command to produce synthetic data.

Usage

gen3s1s generate <path> [--seed N] [--output file] [--format json|yaml|csv|jsonl] [--count N]

Acceptance Criteria

• Compiles Genesis and runs generation
• Respects seed for reproducibility
• Progress bar for long generations
• Multiple output formats
• Validates all constraints during generation