docs(npm-check-fork): fix JSDoc claiming interface extends when it doesn't

[Copilot]

The JSDoc for INpmRegistryPackageResponse incorrectly stated it "extends INpmCheckRegistryData" when the interface doesn't use the extends keyword.

Change:

• Reworded JSDoc to say "structurally compatible with" instead of "extends"

The interface has the same dist-tags and versions fields as INpmCheckRegistryData, making it structurally compatible in TypeScript's type system without formal inheritance.

/**
 * @remarks
 * This interface represents the full response from the npm registry when
 * fetching package metadata. It is structurally compatible with INpmCheckRegistryData
 * to maintain compatibility with existing code like bestGuessHomepage.
 */
export interface INpmRegistryPackageResponse {
  name: string;
  'dist-tags': Record<string, string>;
  versions: Record<string, INpmRegistryVersionMetadata>;
  time?: Record<string, string>;
}

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