build: type CSS-module class names in the apps

[mfal]

A CSS-module import in apps/docs and apps/remote-dom-demo was typed by Next's ambient wildcard (next/types/global) as { readonly [key: string]: string }. A mistyped key — or one taken from the wrong module — therefore type-checked fine and evaluated to undefined at runtime, so React dropped the className with no error anywhere.

packages/components already solved this. This PR extends the same solution to both apps and fixes the seven mismatches it surfaced.

The generator

packages/components/dev/scss-types/generateScssTypes.ts moves to packages/core/src/scssTypes/generateScssTypes.ts, parameterized on package root, source directory and Vite config, and generalized from .module.scss to every flavour vite-plugin-sass-dts handles — .module.sass and .module.css included, which is what the three plain CSS modules in the docs app needed. The components declarations come out byte-identical after the move.

Both apps get a thin entry point. Neither has a Vite setup to borrow, so the plugin gets an inline config: configFile: false, the @/… alias from tsconfig, and deliberately no css.modules.localsConvention — Next hands class names through as authored, which the plugin's default reproduces.

allowArbitraryExtensions in each app's tsconfig is what makes TypeScript resolve ./X.module.scss to ./X.module.d.scss.ts. Without it the declarations are inert and the ambient wildcard silently wins again. Verified against the compiler the apps actually use — TypeScript 7 native, per the >typescript overrides in pnpm-workspace.yaml — both with the flag (typo is an error) and without (typo passes).

nx wiring

• docs — build:scss-types runs before build, dev and test:unit. The test:unit edge is what puts the generator in front of CI's git diff --exit-code; the type check itself rides on pnpm nx build docs in build-previews.yml.
• remote-dom-demo — only before dev. Worth knowing: this app has no build, test or compile target and appears in no workflow, so its declarations are an editor and next dev guard only — CI neither type-checks them nor notices a stale one. Regenerating on dev is what keeps them current. Giving the demo a real build/compile target is a separate question.
• Both targets list the shared generator under inputs, so a change to it invalidates their cache and marks the apps affected (nx show projects --affected confirms).

What it caught

Where	Key	Cause
MobileNavigation.tsx:55	mobileNavigationOffCanvas	reads layout.module.scss, class is in Header.module.scss
MdxFileView.tsx:82	liveCodeEditor	reads customComponents.module.css, class is in LiveCodeEditor.module.css
Footer.tsx:85	feedbackLink	never existed
ComponentCard.tsx:29,33	title, description	never existed
LiveCodeEditor.tsx:315	error	never existed
ExampleTile.tsx:53	mobileCode	never existed

All seven were className={undefined} at runtime, so removing them changes nothing that renders. LiveCodeEditor already applies its own .liveCodeEditor to its root, so MdxFileView's pass-through was redundant on top of being wrong.

One decision worth a second opinion

.mobileNavigationOffCanvas h3 { display: none } in Header.module.scss is deleted rather than wired up. Repointing the import instead would hide the off-canvas modal's "Menü" heading — a visible change to a design that has shipped with the heading since #2338. If UX confirms the heading was meant to be hidden, the fix is to import Header.module.scss in MobileNavigation.tsx and restore the rule.

The third commit removes four classes no TSX ever names (Footer.module.scss's .feedback, .feedbackImage; customComponents.module.css's .preContainer, .preCopyButton). That direction is the one the types do not catch — an unused class is not a type error.

Verification

• pnpm nx build docs green (Next type check), pnpm nx run-many --targets=test:unit,test:compile,test:links --projects=docs,components,core green
• pnpm lint — 0 errors, format check clean
• No generated-code drift after a full build
• Injected styles.crad in ComponentCard.tsx and styles.rootContaner in the demo's layout.tsx: both now fail the type check

🤖 Generated with Claude Code

[github-actions]

Coverage Report for ./packages/components/

Status	Category	Percentage	Covered / Total
🔵	Lines	78.84%	764 / 969
🔵	Statements	78.72%	781 / 992
🔵	Functions	80.28%	171 / 213
🔵	Branches	70.79%	400 / 565

File Coverage

No changed files found.

Generated in workflow #6692 for commit f92168c by the Vitest Coverage Report Action

[github-actions]

🚀 Preview Deployment

Preview environments are ready:

Type	URL
docs	pr-3113.docs.review.flow-components.de
storybook	pr-3113.storybook.review.flow-components.de

Images:

• docs: ghcr.io/mittwald/flow/docs:pr-3113
• storybook: ghcr.io/mittwald/flow/storybook:pr-3113