Summary

• Introduce a terminal-ux-design skill plus a universal terminal-ux-design.instructions.md instruction in the Agentic Copilot layer, and wire the architect, PowerShell developer, and reviewer agents to it so terminal-facing changes get a consistent UX checklist.
• Combine Atlassian's 10 design principles for delightful CLIs with Jakob Nielsen's 10 usability heuristics, framed as "two surfaces, two conventions" so the PowerShell cmdlet surface and the % nova CLI alias surface each get the right idioms.
• Mirror the new skill and instruction into the scaffolded src/resources/agentic-copilot/ tree, regenerate AGENTS.md, fix one bullet-removal regex in scripts/build/Sync-AgenticCopilotScaffold.psd1, and add a guardrail test so the mirror cannot drift.
• Closes feat: introduce terminal-ux-design skill and instruction for delightful command UX #214.

Affected area

• nova CLI or command routing
• Public PowerShell cmdlet behavior
• Scaffolding or project.json handling
• Build, test, analyzer, coverage, or CI helper flow
• Package, raw upload, or package metadata workflow
• Publish, release, or GitHub Actions automation
• Self-update or notification preference behavior
• Contributor documentation (README.md, CONTRIBUTING.md, repository workflow docs)
• End-user docs (docs/*.html)
• Command help (docs/NovaModuleTools/en-US/*.md)
• src/resources/example/
• Dependency or manifest changes (project.json, workflow dependencies, release tooling)
• Security-sensitive change
• Documentation-only change
• Other — Agentic Copilot guidance + scaffold mirror + scaffold-sync guardrail test.

Review guidance

• Start with .github/skills/terminal-ux-design/SKILL.md and .github/instructions/terminal-ux-design.instructions.md to see the new guidance and how it routes work to the skill.
• Then check the agent entry points (.github/agents/architect.agent.md, .github/agents/powershell-developer.agent.md, .github/agents/reviewer.agent.md) and the universal pointer in .github/copilot-instructions.md / regenerated AGENTS.md.
• Confirm the scaffold mirror under src/resources/agentic-copilot/ matches the repo-local copies, including the new files and the regenerated AGENTS.md.
• Review the bullet-removal fix in scripts/build/Sync-AgenticCopilotScaffold.psd1 (trailing \n added to each removal pattern) and the new "documents terminal UX guidance" assertions in tests/AgenticCopilotScaffoldSync.Tests.ps1.
• No public command, CLI route, parameter, output shape, or workflow file was changed.

Validation

• Invoke-NovaBuild
• Test-NovaBuild
• ./scripts/build/Invoke-ScriptAnalyzerCI.ps1
• ./scripts/build/ci/Invoke-NovaModuleToolsCI.ps1
• Targeted Nova workflow validated (% nova build, % nova test, % nova merge, % nova deploy, % nova publish, % nova release, % nova update, % nova notification, or % nova init as relevant)
• Docs/example only; executable validation not needed — covered by the existing pwsh -NoLogo -NoProfile -File ./run.ps1 run after the implementation landed.

Validation notes:

pwsh -NoLogo -NoProfile -File ./run.ps1
  -> ScriptAnalyzer: clean
  -> Invoke-NovaBuild: success
  -> Test-NovaBuild: 1088 passed, 0 failed (includes the new
     `documents terminal UX guidance ...` scaffold-sync test)
No files exercised by tests have been modified since that run,
so the prior result is reused per the prepare-release prompt.

Documentation and release follow-up

• README.md reviewed — already describes .github/skills/ generically; no per-skill update required.
• CONTRIBUTING.md reviewed — already points contributors at .github/skills/, .github/agents/, and .github/instructions/; no update required.
• CHANGELOG.md reviewed and updated — new entry under Unreleased → Added describing the terminal-ux-design skill, instruction, and agent wiring.
• RELEASE_NOTE.md reviewed — no update required. This change is contributor/agent guidance only and does not affect public cmdlet usage, CLI usage, configuration semantics, or migration. The existing Unreleased → Added block already contains real public-API content from prior unreleased work, so the "internal maintenance only" placeholder rule does not apply.
• docs/NovaModuleTools/en-US/ help updated if a public command or CLI behavior changed — n/a, no public surface changed.
• docs/*.html updated if end-user workflows or examples changed — n/a.
• src/resources/example/ reviewed and updated if the real-world project layout, package model, or upload workflow changed — n/a.
• No documentation, changelog, release-note, or example updates were needed.

Maintainability, compatibility, and risk

• Code Health / maintainability impact considered — guidance-only change; the only script edit is a small regex fix in a sync helper, covered by the existing scaffold-sync tests.
• No breaking change
• Breaking change
• Security-sensitive change
• CI, workflow, or release-pipeline impact
• Dependency-review impact

Risk, rollout, or rollback notes:

Low risk. No public PowerShell cmdlet, `nova` CLI route, parameter,
output shape, manifest, package, or workflow behavior changes.
Scaffolded projects created via `nova init` will pick up the new
`terminal-ux-design` skill and instruction on next scaffold or
`nova copilot` refresh; existing scaffolds are unaffected until
maintainers opt in to a refresh.

Rollback: revert this PR. No data, version, manifest, or workflow
state needs to be reconciled.