Fix twoslash in AppHostBuilder; source-control twoslash .d.ts bundle

[IEvangelist]

Summary

The homepage AppHostBuilder component rendered a ts(2307) Cannot find module './.modules/aspire.js' error in the TypeScript view on aspire.dev, while MDX fenced samples (e.g. /get-started/first-app/?aspire-lang=typescript) worked fine. Root cause: Starlight's <Code> component resolves expressive-code config through astro-expressive-code's virtual module, which loses the runtime extraFiles VFS state in production builds. MDX fences flow through rehype-expressive-code with the live ec.config.mjs instance intact — which is why the two paths diverged in prod but behaved identically in dev (shared Vite module graph).

Changes

• Remove meta="twoslash" from AppHostBuilder.astro — it wasn't wanted there anyway, and the component's TS view now renders as plain syntax-highlighted code.
• Source-control the generated type bundle at src/frontend/src/data/twoslash/aspire.d.ts instead of producing it transiently under .twoslash-types/. Diffs are reviewable and dev/build startup is faster (no pre-build generation step).
• Chain regeneration into scripts/update-ts-api.ts so aspire.d.ts stays in sync with src/data/ts-modules/*.json whenever the SDK is re-dumped.
• Drop pnpm twoslash-types from dev/start/build scripts in package.json; the manual pnpm twoslash-types script is kept for ad‑hoc refreshes.
• Update ec.config.mjs, the vitest generator test, .gitignore, and the update-integrations SKILL.md to match the new location and workflow.

Validation

• Unit tests: 6/6 pass (twoslash-types-generator.vitest.test.ts).
• Playwright crawl against localhost:4321 across all 22 docs pages containing twoslash blocks: 0 twoslash errors, hovers render intact (including /app-host/container-registry/ with 194 hovers and /whats-new/aspire-13-2/ with 108 hovers).
• Homepage AppHostBuilder TS view now renders without the ts(2307) error.

Opened as draft for review.

[Copilot]

Pull request overview

Fixes a production-only twoslash resolution issue in the homepage AppHostBuilder TypeScript view by removing twoslash from that component path and moving the generated twoslash .d.ts bundle to a source-controlled location so hover types remain stable across build modes.

Changes:

• Remove meta="twoslash" from the homepage AppHostBuilder code panel to avoid triggering broken twoslash resolution.
• Store the consolidated twoslash declaration bundle under src/data/twoslash/aspire.d.ts and update config/tests/scripts to use it.
• Chain twoslash bundle regeneration into update-ts-api and remove automatic generation from dev/build scripts.

Reviewed changes

Copilot reviewed 7 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/frontend/tests/unit/twoslash-types-generator.vitest.test.ts	Updates the generator test to regenerate/read the now source-controlled aspire.d.ts bundle in place.
src/frontend/src/components/AppHostBuilder.astro	Removes twoslash meta from the homepage code view to prevent the prod-only module resolution failure.
src/frontend/scripts/update-ts-api.ts	Regenerates the twoslash .d.ts bundle after updating ts-modules so hover types stay in sync.
src/frontend/scripts/generate-twoslash-types.ts	Redirects generator output to src/data/twoslash/aspire.d.ts and updates documentation comments.
src/frontend/package.json	Drops pnpm twoslash-types from dev/start/build since the bundle is now checked in.
src/frontend/ec.config.mjs	Points expressive-code-twoslash at the new src/data/twoslash/aspire.d.ts location.
.gitignore	Removes the now-unused .twoslash-types/ ignore entry.
.github/skills/update-integrations/SKILL.md	Documents the new bundle location and the updated regeneration workflow.

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