Fix review findings for info broker removal service FRE-5402

P0 fixes:
- Add CANCELLED status to RemovalStatus enum (types + Prisma schema)
- Use CANCELLED instead of REJECTED for user-initiated cancellations
- Add null guard for req.broker?.name in GET /request/:id
- Remove unsafe 'as any' casts in RemoveBrokersService.ts
- Add type-safe toPersonalInfo() validator for JSON deserialization
- Type RemovalRequestWithBroker properly in getRemovalStatus()
- Fix alert: any to NormalizedAlertInput in BrokerAlertPipeline

P1 fixes:
- Fix admin role check: remove non-existent 'admin', only check 'support'
- Fix BrokerDefinition.category type from string to BrokerCategory
- Add complete OpenAPI spec for all removebrokers routes and schemas

packages/types/src/index.ts

@@ -399,6 +399,7 @@ export const RemovalStatus = {
   COMPLETED: "COMPLETED",
   FAILED: "FAILED",
   REJECTED: "REJECTED",
+  CANCELLED: "CANCELLED",
 } as const;
 export type RemovalStatus = (typeof RemovalStatus)[keyof typeof RemovalStatus];
 
@@ -416,7 +417,7 @@ export interface BrokerDefinition {
   id: string;
   name: string;
   domain: string;
-  category: string;
+  category: BrokerCategory;
   removalMethod: RemovalMethod;
   removalUrl?: string;
   requiresAccount: boolean;