chore: remove dead code and tune frontend chunks

Remove unused production symbols, starter assets, and stale browser tooling; reduce frontend chunk fragmentation.

apps/server/src/bills/dto/bill.dto.ts

@@ -1,4 +1,4 @@
-import { ArrayNotEmpty, IsArray, IsIn, IsInt, IsNotEmpty, IsOptional, IsString, Matches, MaxLength } from 'class-validator';
+import { IsIn, IsNotEmpty, IsOptional, IsString, Matches, MaxLength } from 'class-validator';
 
 export class GenerateBillsDto {
   @IsOptional()
@@ -36,10 +36,3 @@ export class CancelBillDto {
   @MaxLength(300)
   reason: string;
 }
-
-export class BatchUpdateBillStatusDto extends UpdateBillStatusDto {
-  @IsArray()
-  @ArrayNotEmpty()
-  @IsInt({ each: true })
-  ids: number[];
-}