feat: add ce:design skill -- visual design creation between plan and work

[ritvikvarghese]

Summary

• Adds ce:design skill that fills the pipeline gap between /ce:plan and /ce:work
• Supports 5 design tools (Paper, Pencil, Figma, Sketch, Penpot) via runtime detection with graceful fallback to text wireframes
• Complements existing design agents (design-iterator, design-implementation-reviewer, figma-design-sync) -- those handle review/sync, this handles creation

What's included

6 new files, zero modifications to existing files:

skills/ce-design/
├── SKILL.md                     # Main skill (277 lines)
└── references/
    ├── paper-workflow.md        # Paper MCP (live HTML canvas)
    ├── pencil-workflow.md       # Pencil MCP (.pen vector design)
    ├── figma-workflow.md        # Figma MCP (official + Framelink)
    ├── sketch-workflow.md       # Sketch MCP (macOS native)
    └── penpot-workflow.md       # Penpot MCP (open-source)

Design decisions

• Tool-agnostic core -- SKILL.md contains the universal workflow; tool-specific logic lives in reference files
• Runtime detection -- Probes for available MCP tools at invocation time, asks user to choose if multiple detected
• Graceful degradation -- Falls back to text wireframes if no design tool is available
• No new agents -- Leverages existing design agents for review/sync during /ce:work
• Phased approach -- Detect → Understand → Brief → Create → Review → Iterate → Handoff

Compliance

• name matches directory name (ce-design / ce:design)
• description describes what + when to use
• All reference files linked with proper markdown links (no bare backtick refs)
• Imperative/infinitive form, no second person
• Cross-platform question tool with equivalents named (AskUserQuestion, request_user_input, ask_user)
• Fallback for environments without question tool
• Fully-qualified agent references (compound-engineering:design:*)
• SKILL.md under 500 lines (277)
• No version bump in plugin.json
• No CHANGELOG entry
• No modifications to existing files

Test plan

• Install plugin via --plugin-dir and verify /ce:design appears in skill list
• Invoke with Paper MCP available -- verify auto-detection, brief generation, design creation, approval loop
• Invoke with Pencil MCP available -- verify detection and workflow
• Invoke with no design tools -- verify graceful fallback to text wireframes
• Verify reference files load correctly when tool is selected
• Run compliance validation: grep -E '(references|assets|scripts)/[^]+' skills/ce-design/SKILL.md` returns nothing

🤖 Generated with Claude Code

[kieranklaassen]

This is cool, thank you. We already have some design things, but let me look at it and see if we can consolidate everything. I want to make some improvements to the design side, so this is great. I've been using it a lot for design lately. What are your favorite flows for design?

[ritvikvarghese]

hey Kieran, thank you! the workflow i use the most is CLI, claude code to paper. usually like to see the UI in paper first and give feedback to claude on what to change.

I assumed people might be using other design tools, so integrated those as well.

[tmchow]

I think the key thing for this skill is what shape it takes in compound engineering. Thre are many ways to approach this including the way you have with the various MCPs. I've been fond lately of having the frontier models do the work directly without MCPs, but there's likely a multipronged approach to take here which gives a lot of flexibility to work in the way that someone wants. But we have to thread the needle carefully.