fix(investments): align roles and date contracts

Identify income dependencies by role and document screen-specific dates.
Convert inclusive calendar days into half-open source ranges while
preserving operation timestamps and existing stored coverage.

src/modules/investments/upcoming-events/upcoming-events.dto.ts

@@ -10,7 +10,8 @@ import { AccountReferenceDto } from '../account-reference.dto';
 export class UpcomingEventsQueryDto extends InvestmentReadQueryDto {
   @ApiPropertyOptional({
     format: 'date',
-    description: 'Inclusive start date (YYYY-MM-DD). Defaults to today in UTC.',
+    description:
+      'Inclusive UTC calendar start date (YYYY-MM-DD). May be supplied independently; defaults to today in UTC.',
   })
   @IsOptional()
   @Matches(/^\d{4}-\d{2}-\d{2}$/)
@@ -20,7 +21,7 @@ export class UpcomingEventsQueryDto extends InvestmentReadQueryDto {
   @ApiPropertyOptional({
     format: 'date',
     description:
-      'Inclusive end date (YYYY-MM-DD). Defaults to 30 days after from.',
+      'Inclusive UTC calendar end date (YYYY-MM-DD). May be supplied independently; defaults to 30 days after from. Timestamp queries use the start of the following UTC day as the exclusive end.',
   })
   @IsOptional()
   @Matches(/^\d{4}-\d{2}-\d{2}$/)