feat: Add BetterChat + TimedExecute plugin config modules

- DB migrations 017 (betterchat_configs) and 020 (timedexecute_configs) applied
- TypeORM entities matching production schema exactly
- NestJS modules with full CRUD + apply-to-server + import-from-server
- Pinia stores following teleport config pattern
- BetterChatView: Chat Groups editor with color pickers, font sizes, format strings; Settings tab with word filter, anti-flood, player tagging
- TimedExecuteView: TimerRepeat with presets, RealTime-Timer, OnConnect/OnDisconnect command lists
- Wired into app.module.ts, router, DashboardLayout nav

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

backend-nest/src/modules/timedexecute/timedexecute.module.ts

@@ -0,0 +1,14 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { TimedExecuteController } from './timedexecute.controller';
+import { TimedExecuteService } from './timedexecute.service';
+import { TimedExecuteConfig } from '../../entities/timedexecute-config.entity';
+import { NatsService } from '../../services/nats.service';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([TimedExecuteConfig])],
+  controllers: [TimedExecuteController],
+  providers: [TimedExecuteService, NatsService],
+  exports: [TimedExecuteService],
+})
+export class TimedExecuteModule {}