修复: DeepSeek 400 全量扫描 + 队列 per-conv 隔离

- openai_compat: 扫描所有 assistant 消息剥离 orphan tool_calls（原仅查末条）
- queue 加 conversationId 字段，按会话精准 drain
- regenerate/editMessage 只清本会话排队消息
- newConversation 保留旧会话排队消息
- AiError 只清出错会话的队列项

src-tauri/tauri.conf.json

@@ -5,6 +5,7 @@
   "build": {
     "beforeDevCommand": "bun dev",
     "beforeBuildCommand": "bun run build",
+    "devUrl": "http://localhost:1420",
     "frontendDist": "../dist"
   },
   "app": {