feat: implement QuestionBank CRUD with pagination and template query

- Add pagination support to findAll (page, limit query params)
- Add findByTemplateId method to service
- Add GET /by-template/:templateId endpoint to controller
- Service already includes CRUD for QuestionBank and QuestionBankItem

server/src/model-config/dto/create-model-config.dto.ts

@@ -0,0 +1,92 @@
+// server/src/model-config/dto/create-model-config.dto.ts
+import {
+  IsBoolean,
+  IsEnum,
+  IsNotEmpty,
+  IsNumber,
+  IsOptional,
+  IsString,
+  IsUrl,
+  Max,
+  Min,
+  MinLength,
+} from 'class-validator';
+import { ModelType } from '../../types';
+
+export class CreateModelConfigDto {
+  @IsString()
+  @IsNotEmpty()
+  name: string;
+
+  @IsString()
+  @IsNotEmpty()
+  modelId: string;
+
+  @IsUrl({ require_tld: false }, { message: 'Base URL must be a valid URL' })
+  @IsOptional()
+  baseUrl?: string;
+
+  @IsString()
+  @IsOptional()
+  apiKey?: string; // API key is optional - allows local models
+
+  @IsEnum(ModelType)
+  @IsNotEmpty()
+  type: ModelType;
+
+  @IsNumber()
+  @Min(1, { message: 'Minimum vector dimension is 1' })
+  @Max(4096, {
+    message: 'Maximum vector dimension is 4096 (Elasticsearch limit)',
+  })
+  @IsOptional()
+  dimensions?: number;
+
+  // ==================== Additional Fields ====================
+
+  /**
+   * Model input token limit (only valid for embedding/rerank)
+   */
+  @IsNumber()
+  @Min(1)
+  @Max(100000)
+  @IsOptional()
+  maxInputTokens?: number;
+
+  /**
+   * Batch processing limit (only valid for embedding/rerank)
+   */
+  @IsNumber()
+  @Min(1)
+  @Max(10000)
+  @IsOptional()
+  maxBatchSize?: number;
+
+  /**
+   * Whether this is a vector model
+   */
+  @IsBoolean()
+  @IsOptional()
+  isVectorModel?: boolean;
+
+  /**
+   * Model provider name
+   */
+  @IsString()
+  @IsOptional()
+  providerName?: string;
+
+  /**
+   * Whether to enable this model
+   */
+  @IsBoolean()
+  @IsOptional()
+  isEnabled?: boolean;
+
+  /**
+   * Whether to use this model as default
+   */
+  @IsBoolean()
+  @IsOptional()
+  isDefault?: boolean;
+}

server/src/model-config/dto/model-config-response.dto.ts

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+// server/src/model-config/dto/model-config-response.dto.ts
+import { Exclude, Expose, Transform } from 'class-transformer';
+import { ModelConfig } from '../model-config.entity';
+
+export class ModelConfigResponseDto {
+  id: string;
+  name: string;
+  provider: string;
+  modelId: string;
+  baseUrl?: string;
+
+  @Transform(({ value }) => (value ? '********' : undefined))
+  apiKey?: string;
+
+  type: string;
+  isEnabled?: boolean;
+  isDefault?: boolean;
+  createdAt: Date;
+  updatedAt: Date;
+
+  constructor(partial: Partial<ModelConfig>) {
+    Object.assign(this, partial);
+  }
+}

server/src/model-config/dto/update-model-config.dto.ts

@@ -0,0 +1,5 @@
+// server/src/model-config/dto/update-model-config.dto.ts
+import { PartialType } from '@nestjs/mapped-types';
+import { CreateModelConfigDto } from './create-model-config.dto';
+
+export class UpdateModelConfigDto extends PartialType(CreateModelConfigDto) {}