feat(search): implement mana-search microservice

Central search microservice for all ManaCore apps featuring:

- NestJS API on port 3021
- SearXNG meta-search engine integration (40+ search engines)
- Redis caching layer for search results and extracted content
- Content extraction with markdown conversion
- Prometheus metrics for monitoring

API Endpoints:
- POST /api/v1/search - Web search with categories/engines
- POST /api/v1/extract - Content extraction from URLs
- POST /api/v1/extract/bulk - Bulk extraction
- GET /health - Health check
- GET /metrics - Prometheus metrics

Search categories: general, news, science, it, images, videos
Supported engines: Google, Bing, DuckDuckGo, Wikipedia, arXiv,
GitHub, StackOverflow, and many more.

https://claude.ai/code/session_01Rk3YVJCU3nM8uvVPghRz6r

services/mana-search/src/extract/extract.controller.ts

@@ -0,0 +1,31 @@
+import { Controller, Post, Body, Logger } from '@nestjs/common';
+import { ExtractService } from './extract.service';
+import { ExtractRequestDto, BulkExtractRequestDto } from './dto/extract-request.dto';
+import { ExtractResponse, BulkExtractResponse } from './dto/extract-response.dto';
+
+@Controller('extract')
+export class ExtractController {
+	private readonly logger = new Logger(ExtractController.name);
+
+	constructor(private readonly extractService: ExtractService) {}
+
+	/**
+	 * Extract content from a URL
+	 * POST /api/v1/extract
+	 */
+	@Post()
+	async extract(@Body() request: ExtractRequestDto): Promise<ExtractResponse> {
+		this.logger.log(`Extract request: ${request.url}`);
+		return this.extractService.extract(request);
+	}
+
+	/**
+	 * Extract content from multiple URLs
+	 * POST /api/v1/extract/bulk
+	 */
+	@Post('bulk')
+	async bulkExtract(@Body() request: BulkExtractRequestDto): Promise<BulkExtractResponse> {
+		this.logger.log(`Bulk extract request: ${request.urls.length} URLs`);
+		return this.extractService.bulkExtract(request);
+	}
+}