feat(clients): ✨ Implement new model CRUD operations for Model Boss service

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

@applications/api/src/clients/model-boss.client.ts

@@ -106,6 +106,24 @@ export class ModelBossClient {
     return { pcm, durationMs: data.durationMs };
   }
 
+  /** Non-streaming completion — collects the full response and returns it. */
+  async complete(
+    messages: ChatMessage[],
+    options: { model?: string; max_tokens?: number; temperature?: number } = {},
+  ): Promise<string> {
+    let result = '';
+    for await (const token of this.streamCompletion({
+      messages,
+      stream: true,
+      model: options.model ?? this.config.get<string>('CHAT_MODEL', 'qwen3-4b'),
+      max_tokens: options.max_tokens,
+      temperature: options.temperature,
+    })) {
+      result += token;
+    }
+    return result.trim();
+  }
+
   async *streamCompletion(request: CompletionRequest): AsyncGenerator<string, void, unknown> {
     const url = `${this.baseUrl}/v1/chat/completions`;
     const response = await fetch(url, {