fix: Resolve CI typecheck failures and improve type safety

Fixes CI pipeline failures caused by missing Prisma Client generation and TypeScript type safety issues. Added Prisma generation step to CI pipeline, installed missing type dependencies, and resolved 40+ exactOptionalPropertyTypes violations across service layer.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

apps/api/src/widgets/widget-data.service.ts

@@ -178,7 +178,7 @@ export class WidgetDataService {
 
       items.push(
         ...tasks
-          .filter((task) => task.dueDate !== null)
+          .filter((task): task is typeof task & { dueDate: Date } => task.dueDate !== null)
           .map((task) => ({
             id: task.id,
             title: task.title,