Add winapp-maui skill for the MAUI resizetizer manifest dependency

[pictos]

Summary

Adds a dedicated winapp-maui skill that documents how to package and sign .NET MAUI Windows apps with winapp, focused on solving the resizetizer manifest dependency.

The problem it solves

A .NET MAUI project ships a source manifest at Platforms/Windows/Package.appxmanifest full of MAUI-specific $placeholder$ tokens (DisplayName, Logo, Identity Name/Publisher/Version, tile/splash logos). winapp package only auto-resolves its own $targetnametoken$/$targetentrypoint$ tokens — it does not understand MAUI's $placeholder$ tokens, so pointing it at the source manifest fails with:

manifest contains unresolved placeholders: $placeholder$

MAUI's resizetizer (bundled with the MAUI workload) fills those tokens at build/publish time into generated manifests:

• obj\<Config>\<TFM>\<RID>\resizetizer\m\Package.appxmanifest (MAUI tokens resolved; entry-point tokens remain, resolved by --executable)
• bin\<Config>\<TFM>\<RID>\AppxManifest.xml (fully resolved)

The fix is to point winapp package --manifest at the generated manifest, never the source one — and never hand-edit the source manifest (the resizetizer overwrites its generated copy each build).

What's included

• New skill fragment docs/fragments/skills/winapp-cli/maui.md and generated SKILL.md in .github/plugin/skills/winapp-cli/maui/ and .claude/skills/winapp-maui/. Covers: root cause, where the resolved manifest lives, publish→pack→sign workflow, publisher/cert matching, a full GitHub Actions CI example (x64 + arm64, self-contained), tips, and a troubleshooting table.
• Registered maui in scripts/generate-llm-docs.ps1 ($SkillNames, $SkillDescriptions, $SkillCommandMap = empty — links to guidance, like frameworks) and in scripts/validate-llm-docs.ps1.
• Cross-links from winapp-frameworks (guides table row + ### .NET MAUI note + related-skills bullet) and winapp-troubleshoot (error-table row + related-skills bullet).

Validation

• Generated SKILL.md files verified byte-identical to generate-llm-docs.ps1 output (ignoring the version line, which the release build stamps).
• .claude/skills/winapp-maui/SKILL.md verified byte-identical to the plugin source (what sync-claude-plugin.ps1 produces).
• Guidance validated end-to-end against a real MAUI app (LogViewer) with WinAppCLI 0.4.0: reproduced the placeholder failure, then produced a signed MSIX with 0 unresolved placeholders by pointing --manifest at the resizetizer manifest.

[Copilot]

Pull request overview

This PR adds a new dedicated Copilot/Claude agent skill, winapp-maui, documenting how to package and sign .NET MAUI Windows apps with winapp. Its central purpose is to explain the "resizetizer manifest dependency": MAUI's source Platforms/Windows/Package.appxmanifest is full of $placeholder$ tokens that winapp package does not resolve, so users must point --manifest at the resizetizer-generated manifest instead. The skill fits into the repo's auto-generated docs pipeline (fragment → plugin SKILL.md → .claude mirror) and cross-links into the existing winapp-frameworks and winapp-troubleshoot skills.

Changes:

• Adds the maui.md skill fragment plus its generated SKILL.md in .github/plugin/skills/winapp-cli/maui/ and .claude/skills/winapp-maui/.
• Registers maui in the doc-generation and validation scripts (generate-llm-docs.ps1, validate-llm-docs.ps1).
• Adds cross-links (frameworks table row + .NET MAUI section, troubleshoot error-table row, related-skills bullets) across the frameworks/troubleshoot fragments and their generated mirrors.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
docs/fragments/skills/winapp-cli/maui.md	New hand-written skill fragment: root cause, manifest locations, publish→pack→sign workflow, CI example, troubleshooting.
.github/plugin/skills/winapp-cli/maui/SKILL.md	Generated Copilot plugin skill (frontmatter + fragment body); verified identical to fragment.
.claude/skills/winapp-maui/SKILL.md	Claude mirror of the plugin skill; verified byte-identical to the plugin SKILL.md.
scripts/generate-llm-docs.ps1	Registers maui in $SkillNames, $SkillDescriptions, and $SkillCommandMap (empty, like frameworks).
scripts/validate-llm-docs.ps1	Adds maui to the skill-drift validation list.
docs/fragments/skills/winapp-cli/frameworks.md	Adds a .NET MAUI table row/section and a related-skills link to winapp-maui.
.github/plugin/skills/winapp-cli/frameworks/SKILL.md	Generated mirror of the frameworks fragment changes.
.claude/skills/winapp-frameworks/SKILL.md	Claude mirror of the frameworks changes.
docs/fragments/skills/winapp-cli/troubleshoot.md	Adds a MAUI placeholder-error row and related-skills link.
.github/plugin/skills/winapp-cli/troubleshoot/SKILL.md	Generated mirror of the troubleshoot changes.
.claude/skills/winapp-troubleshoot/SKILL.md	Claude mirror of the troubleshoot changes.

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[nmetulev]

🤖 AI-generated PR review

This review was produced by an automated multi-dimensional review agent (GitHub Copilot CLI) with a second-model cross-check. Everything below is a suggestion, not a mandate — the author decides what to implement, defer, or dismiss. Nothing here blocks merge, and any individual item may be wrong or simply not worth the churn. Specific items are attached as inline comments.

Verdict

Solid, well-written skill. I built the CLI and ran scripts/validate-llm-docs.ps1 → exit 0: the maui skill regenerates with zero drift, and the .github/plugin and .claude mirrors are byte-identical to the fragment. 0 critical · 0 high · 4 medium · 2 low.

Finding not tied to a diff line

M2 · llms.txt (lines 16-24) · docs sync — medium. The hand-maintained "Copilot Plugin Skills" list enumerates every skill but omits the new maui/SKILL.md, and no script regenerates llms.txt, so it won't self-heal. Suggestion: add a maui/SKILL.md entry between the frameworks and ui-automation lines.

Inline comments (author's discretion)

• M1 maui.md — the "preferred" bin\…\AppxManifest.xml + the no---manifest shortcut don't hold for the WindowsPackageType=None flow the skill documents (medium; originally high, downgraded on cross-check).
• M3 frameworks.md — standalone winapp-maui skill vs the frameworks+guide convention (medium, design call).
• M4 validate-llm-docs.ps1 — pre-existing: validate list omits ui-automation (medium).
• L1 / L2 maui.md — CI cert-cleanup and password-handling nits (low).

Verified clean

CLI UX — every command/flag in the skill matches cli-schema.json (package → --cert/--cert-password; sign → positional cert + --password; cert generate --manifest). Plugin generation pipeline — both mirrors generate, description + version match the script.

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🤖 Generated by an AI review agent — advisory only. Feel free to close anything that isn't worth it.