next.js

4580da17 - Replace WorkStore isStaticGeneration with executionMode (#96570)

Replace WorkStore isStaticGeneration with executionMode (#96570) ## Summary - replace `WorkStore.isStaticGeneration` with an explicit `'prerender' | 'request'` execution mode - preserve the existing derivation and behavior while making the render/prerender distinction explicit - document that prerendering includes both build-time generation and runtime revalidation - establish groundwork for moving the render decision higher in the stack and replacing downstream mode checks with purpose-specific state Stacked on #96564.