refactor: remove DeepSeek fallback — Hermes only; fail fast on error

src/modules/admin-ai-chat/admin-ai-chat.module.ts

@@ -1,12 +1,11 @@
-import { Module } from '@nestjs/common';
+import { Module } from '@nestjs/common';
 import { AdminAiChatController } from './admin-ai-chat.controller';
 import { AdminAiChatService } from './admin-ai-chat.service';
-import { DeepSeekProvider } from '../ai/providers/deepseek.provider';
 import { AdminAuthGuard } from '../../common/guards/admin-auth.guard';
 import { AdminRolesGuard } from '../../common/guards/admin-roles.guard';
 
 @Module({
   controllers: [AdminAiChatController],
-  providers: [AdminAiChatService, DeepSeekProvider, AdminAuthGuard, AdminRolesGuard],
+  providers: [AdminAiChatService, AdminAuthGuard, AdminRolesGuard],
 })
 export class AdminAiChatModule {}

src/modules/admin-ai-chat/admin-ai-chat.service.ts

@@ -1,5 +1,4 @@
-import { Injectable, Logger } from '@nestjs/common';
-import { DeepSeekProvider } from '../ai/providers/deepseek.provider';
+import { Injectable, Logger } from '@nestjs/common';
 import type { AiChatDto } from './dto/ai-chat.dto';
 
 const HERMES_API_URL = 'http://10.2.0.7:8642/v1/chat/completions';
@@ -10,7 +9,7 @@ const SYSTEM_PROMPT = '你是知习管理后台的 AI 任务助理，帮助管
 export class AdminAiChatService {
   private readonly logger = new Logger(AdminAiChatService.name);
 
-  constructor(private readonly deepseek: DeepSeekProvider) {}
+  constructor() {}
 
   async chat(dto: AiChatDto) {
     const systemMessages = dto.messages.filter(m => m.role === 'system');
@@ -20,13 +19,7 @@ export class AdminAiChatService {
       ? dto.messages
       : [{ role: 'system' as const, content: SYSTEM_PROMPT }, ...dto.messages];
 
-    // Try Hermes Agent first, fall back to DeepSeek
-    try {
-      return await this.callHermes(messages);
-    } catch (err: any) {
-      this.logger.warn('Hermes unavailable, falling back to DeepSeek: ' + err.message);
-      return await this.callDeepSeek(messages);
-    }
+    return await this.callHermes(messages);
   }
 
   private async callHermes(messages: Array<{ role: string; content: string }>) {
@@ -47,7 +40,8 @@ export class AdminAiChatService {
     });
 
     if (!resp.ok) {
-      throw new Error('Hermes returned ' + resp.status);
+      const text = await resp.text().catch(() => '');
+      throw new Error(`Hermes API error ${resp.status}: ${text}`);
     }
 
     const data = await resp.json();
@@ -59,18 +53,6 @@ export class AdminAiChatService {
     return { content, usage: { model: 'hermes-agent', inputTokens: usage.prompt_tokens, outputTokens: usage.completion_tokens } };
   }
 
-  private async callDeepSeek(messages: Array<{ role: string; content: string }>) {
-    const start = Date.now();
-    const result = await this.deepseek.generate({
-      model: 'deepseek-chat',
-      messages: messages as Array<{ role: 'system' | 'user' | 'assistant'; content: string }>,
-      temperature: 0.7,
-      maxTokens: 4096,
-    });
-    this.logger.log('DeepSeek chat: ' + (Date.now() - start) + 'ms');
-    return { content: result.rawText, usage: result.usage };
-  }
-
   getDashboardConfig() {
     return {
       url: 'http://10.2.0.7:9119',