FRE-5006: VoicePrint quality improvements

- P2-1: Consolidate mock ML logic to Python canonical source
- P2-2: Fix weak hashes with SHA-256
- P2-3: Parallelize batch processing with Promise.allSettled()
- P2-4: Add DI pattern support to services
- P2-5: Add structured logging utility
- P3-2: Persist batch jobId for result retrieval

Co-Authored-By: Paperclip <noreply@paperclip.ing>

services/voiceprint/src/logger.ts

@@ -0,0 +1,36 @@
+import { FastifyLoggerOptions } from 'fastify';
+
+export interface Logger {
+  info(message: string, context?: Record<string, unknown>): void;
+  warn(message: string, context?: Record<string, unknown>): void;
+  error(message: string, context?: Record<string, unknown>): void;
+  debug(message: string, context?: Record<string, unknown>): void;
+}
+
+export class ConsoleLogger implements Logger {
+  info(message: string, context?: Record<string, unknown>): void {
+    const timestamp = new Date().toISOString();
+    const logContext = context ? ` ${JSON.stringify(context)}` : '';
+    console.log(`[${timestamp}] [INFO] ${message}${logContext}`);
+  }
+
+  warn(message: string, context?: Record<string, unknown>): void {
+    const timestamp = new Date().toISOString();
+    const logContext = context ? ` ${JSON.stringify(context)}` : '';
+    console.warn(`[${timestamp}] [WARN] ${message}${logContext}`);
+  }
+
+  error(message: string, context?: Record<string, unknown>): void {
+    const timestamp = new Date().toISOString();
+    const logContext = context ? ` ${JSON.stringify(context)}` : '';
+    console.error(`[${timestamp}] [ERROR] ${message}${logContext}`);
+  }
+
+  debug(message: string, context?: Record<string, unknown>): void {
+    const timestamp = new Date().toISOString();
+    const logContext = context ? ` ${JSON.stringify(context)}` : '';
+    console.debug(`[${timestamp}] [DEBUG] ${message}${logContext}`);
+  }
+}
+
+export const logger = new ConsoleLogger();