scripts/check/angular/

gate	fails when
check-angular.ts	the layer stops typechecking under ngc --strictTemplates. A green compile is a claim about types, and never about behaviour.
check-angular-demos.ts	a component has no <Name>.demo.generated.html and <Name>.demo.entry.generated.ts beside it, or its page loads a module other than the bundle that entry compiles to. There is no coverage list, because every component has a page: the inventory is the component tree, so a page cannot go missing behind a list and a list cannot go stale. Structural and portable, needing no browser and no bundler, because the pages' script is git-ignored build output, and a blank page would pass a viewport check by having nothing to overflow. Whether a page RENDERS is held by nothing.
check-assertions.ts	an Angular suite compares DOM nodes with an equality assertion. node:assert renders both operands into its diff, and a connected happy-dom node reaches the whole document from there. With one document shared across the run, a failing identity assertion is what exhausts the run rather than what reports the defect.
check-cdk.ts	the CDK overlay bridge overrides a rule that overrides nothing, names a token that resolves to nothing, or targets a class the CDK has renamed upstream. It examines the selectors, which it can because the prebuilt sheet is the oracle; what it still cannot check is whether the override is the right value.
check-boolean-inputs.ts	a boolean signal input is declared without transform: booleanAttribute, so the bare-attribute spelling every other boolean in the layer answers to fails to compile against that one. An input is boolean by its type argument or by a default of true/false, because the layer declares it both ways. NOT_AN_ATTRIBUTE names what is boolean by type and is deliberately not an attribute, with its reason, and an entry fails once it stops being needed, whether the input gained the transform or went away.
check-optional-inputs.ts	a defaulted signal input carries no transform, so its write type excludes undefined and a consumer holding an optional value has to restate the default the component already owns. The remedy is one shape, { transform: (value) => value ?? <default> }, which widens what may be bound and leaves what is read alone. TAKES_NO_ABSENCE is empty, and that emptiness is the claim: no member in the layer needs a bound absence to mean something other than its default.

Every X.test.ts beside a gate covers that gate.