Re-enable component specs (NgModule → standalone or module-scope fix)

[Yicong-Huang]

Task Summary

Re-enable the 43 *.component.spec.ts files that #4862 had to exclude. The new @angular/build:unit-test builder type-checks each component's template against the bundle's standalone scope (not the declaring NgModule's scope), so NgModule-declared components fail to resolve their template directives — [ngModel], <nz-dropdown-menu>, custom selectors like <texera-user-avatar>, etc. ~1000 NG8002/NG8001/NG8004 errors before exclusion.

Two viable approaches

A. Convert components to standalone (Angular's recommended direction)

For each affected component:

1. @Component({ standalone: false, ... }) → @Component({ standalone: true, imports: [CommonModule, FormsModule, ...moduleSpecificModules], ... })
2. Remove the component from the declaring NgModule's declarations array; add to imports instead.

Pros: future-proof, matches Angular team direction, eliminates the implicit NgModule scope dependency.
Cons: per-component imports list must be derived from what each template uses; ~43 components to migrate.

B. Schema overrides at the spec level

For each component spec, add schemas: [CUSTOM_ELEMENTS_SCHEMA] to TestBed setup so the strict template checker tolerates unknown elements.

Pros: faster to apply.
Cons: silently masks real bugs (typos in element names won't fail tests), and only addresses NG8001-style errors — [ngModel] not being resolved is NG8002 which schemas don't suppress.

Recommendation: A. Doing this in chunks (group by feature area) keeps each PR reviewable.

Affected files

43 files matching **/*.component.spec.ts. Currently excluded by tsconfig.spec.json and angular.json's test-target exclude.

Definition of done

• All 43 component specs compile under the unit-test builder
• Each runs to either passing or a documented runtime issue (likely a separate follow-up)
• Exclusion entries removed from tsconfig.spec.json and angular.json