feat: Add FTW skill - structured development with PIV workflow

[SmokeAlot420]

Summary

Adds FTW (First Try Works) as a community-contributed skill for structured software development using the Plan-Implement-Validate (PIV) workflow.

What FTW does:

• Orchestrates multi-agent software development with specialized sub-agents for execution, validation, and debugging
• Ships working code on the first try through comprehensive planning (PRPs) and independent validation
• Three modes: full multi-phase (/ftw), lightweight discovery-driven (/ftw mini), and project setup (/ftw init)
• Automated debug loops (max 3x) when validation finds gaps, with escalation to human when needed

Key differentiator: Independent validator agent that verifies all requirements against the PRP without trusting executor claims — the "V" in PIV.

Also available on ClawHub and as a Claude Code plugin.

File Structure

ftw/
├── SKILL.md                          # Main skill definition (full, mini, init modes)
├── references/
│   ├── workflow-full.md              # Full PIV phase workflow with sub-agent templates
│   ├── workflow-mini.md              # Mini discovery-driven workflow
│   ├── codebase-analysis.md          # Codebase analysis process for PRP creation
│   ├── create-prd.md                 # PRD generation guide
│   ├── generate-prp.md              # PRP generation with research integration
│   ├── execute-prp.md               # PRP execution process
│   ├── piv-executor.md              # Executor sub-agent definition
│   ├── piv-validator.md             # Validator sub-agent definition
│   └── piv-debugger.md              # Debugger sub-agent definition
└── assets/
    ├── prp_base.md                   # PRP template with validation loops
    └── workflow-template.md          # Project workflow tracker template

Changes

• Added ftw/ directory with SKILL.md, 8 reference files, and 2 asset files (12 files total)
• Updated README.md to add FTW to the Available Skills table

Links

• GitHub: https://github.com/SmokeAlot420/ftw
• Skill requires: git
• Supported OS: macOS, Linux