feat: Add RaidableBases plugin config module — DB migration, NestJS CRUD, Vue editor

- Migration 021: raidablebases_configs table with JSONB config_data
- Entity, module, controller (7 endpoints), service with NATS deploy/import
- Frontend: 4-tab editor (General, Difficulty, NPC, Loot & Rewards)
- Pinia store, types, router route, sidebar nav with Swords icon
- Top 30 most common settings with actual RaidableBases.json key paths
- Difficulty sub-tabs for Easy/Medium/Hard/Expert/Nightmare with spawn day toggles

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend-nest/src/modules/raidablebases/dto/create-raidablebases-config.dto.ts

@@ -0,0 +1,19 @@
+import { IsString, IsOptional, IsObject, MaxLength } from 'class-validator';
+import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
+
+export class CreateRaidableBasesConfigDto {
+  @ApiProperty({ example: 'Default RaidableBases Config' })
+  @IsString()
+  @MaxLength(100)
+  config_name: string;
+
+  @ApiPropertyOptional({ example: 'Standard RaidableBases settings' })
+  @IsString()
+  @IsOptional()
+  description?: string;
+
+  @ApiPropertyOptional()
+  @IsObject()
+  @IsOptional()
+  config_data?: Record<string, any>;
+}