docs: refresh App workshop with learner-created skills and QA

[GeekTrainer]

Summary

Layer 2/4, based on #169 (geektrainer/authoring-guidance-pr), refreshes the App workshop and five translations with setup, star ratings, instructions, filtering, learner-created quality-checks skill, MCP, QA, feature merge, repository-backed canvas, and recap. This replacement draft preserves historical #172, which GitHub indirectly marked merged into CLI during the earlier reorder; nothing reached main.

Current stack order: #169 → #174 → #170 → #171 (native stack #175). The App patch is unchanged after rebasing onto #169's simplified verification guidance and wrappers: six App language trees and eight shared App-scoped changes (the AUTHORING structure-tree line, App descriptions in six landing pages, and App sidebar), totaling 104 raw paths / 102 rename-aware paths.

Type of change

• Workshop content (lesson Markdown, images)
• Site shell (website/ Astro + Starlight wrapper)
• Copilot configuration (.github/copilot-instructions.md, instructions, agents, skills)
• Repo housekeeping (CI, dependabot, README, license)
• Other:

Verification

• Type checks and a clean site build pass (historical App run below; not rerun for this unchanged-content rebase).
• Affected pages and translations match their source and intended routes (historical inspection; lesson bytes preserved).
• Offline internal link checks pass (historical App run below).
• Changed external links have been checked separately (historical prepared-App evidence below).

Current rebase checks: App commit 2f36fcb3a1f99565f84dd5a09aeda3d6a12cfeba has exact parent #169 at 7407858a6bf8c994073b4876d7e4d99c3dd540e5 and tree a33033a37076b0213bc52fc15a9023f5c37271df. Range-diff confirms the App patch is unchanged. All lesson bytes, AUTHORING content, and frozen prompts match the previous App commit. Inherited tooling, package metadata, and loader match #169 unchanged; the site config differs from #169 only by the existing App sidebar delta. The previous App HEAD is preserved at refs/simple-verification/original/174. Publication used an explicit old-SHA force-with-lease.

Simplified verification inherited from #169: small verify.sh and verify.ps1 wrappers reuse existing check:all, build, and offline Lychee commands. The four MJS engine files, capture hooks, and direct parser dependency are removed; original transitive dependency resolutions are preserved. Source/rendered-content inspection is an AI/manual review responsibility, not an exact-HTML verification engine. The owning #169 session reported successful actual Bash wrapper execution and failure probes. PowerShell is not installed and remains unverified. This unchanged-content App rebase did not rerun site commands; final top-of-stack wrapper execution belongs to the coordinating session.

Historical App execution on September 14, 2026: at previous App commit b0bfbc729fe1ffc4c2a5beaeedb0ccfb90ea0b90, the then-present verify.mjs all passed with exit 0: check:all reported zero errors, zero warnings, and four existing Astro hints; the clean build produced 230 pages; the old engine checked 228 source-derived content pages; offline links reported 19,184 total / 2,797 unique / zero errors. These are historical results, not claims about functionality of the current wrappers. The old exact-content engine has been removed. The temporary dependency link was removed after that run.

Earlier prepared-App evidence at c681efd10b3ddf04e38a63ad4b917c8397687bdf: the owning session inspected 78 affected App/landing routes across six languages, 1,752 paragraphs, 168 rendered fences, and absence of all 24 removed routes. Four frozen English prompt digests matched, skill CREATE remained 184 words, translated fences/source bytes matched the pinned source, external skill links returned HTTP 200, and stale-route/content-alignment sweeps found no remaining drift. Those external-link, prompt-digest, and rendered-content checks were not newly rerun for this tooling-only rebase.

Screenshots

Not applicable to this verification simplification sync: no additional curriculum or rendering changes were made.

Notes for reviewers

Keep this PR draft. The coordinating session owns stack metadata; order and base refs remain #169 → #174 → #170 → #171. Historical closed #172, its old branch/session, and source #167 are preserved and untouched; #167 retains the original review/runtime history. No merges into main or template changes are included. Template dependencies remain github-samples/tailspin-toys#97 and github-samples/tailspin-toys#91.

The App tree above is the standalone layer-2 tree, not the final full-stack tree. Curriculum remains unchanged from original pinned snapshot e150fd531805f57a77be754c37f342386471bc00, with simplified #169 guidance and verification wrappers inherited. Final full-stack identity and verification are owned by the coordinating session.

Historical Bash/macOS Sonnet and MAI skill trials in #167 are not fresh App QA or UI certification. Native PowerShell, the broader QA matrix, App agent-picker/hot discovery, and a full UI rehearsal remain unverified. Existing callout bodies remain plain divs rather than styled asides; that rendering caveat is unchanged. Learner skill RUN/QA/prompts are unchanged; this App layer adds no further scripts or skill alterations. No installs, new test frameworks, previews, runtime trials, or UI certification were performed for this sync.