refactor: centralize domain values and enforce numeric lint

src/modules/investments/tbank-connection/tbank-connection.controller.ts

@@ -4,6 +4,7 @@ import {
   Delete,
   Get,
   HttpCode,
+  HttpStatus,
   Put,
   Req,
   UseGuards,
@@ -47,7 +48,7 @@ export class TbankConnectionController {
   }
 
   @Delete()
-  @HttpCode(204)
+  @HttpCode(HttpStatus.NO_CONTENT)
   @ApiNoContentResponse()
   delete(@Req() request: Request & { user: AccessPayload }): Promise<void> {
     return this.connection.delete(request.user.sub);

src/modules/investments/tbank-connection/tbank-connection.dto.ts

@@ -1,11 +1,13 @@
 import { ApiProperty } from '@nestjs/swagger';
 import { IsNotEmpty, IsString, MaxLength } from 'class-validator';
 
+const MAX_TOKEN_LENGTH = 4096;
+
 export class PutTbankConnectionDto {
   @ApiProperty({ writeOnly: true })
   @IsString()
   @IsNotEmpty()
-  @MaxLength(4096)
+  @MaxLength(MAX_TOKEN_LENGTH)
   declare token: string;
 }