fix: fallback without tools on tool_use_failed error

app/api/voice/chat/route.ts

@@ -164,10 +164,29 @@ export async function POST(req: Request) {
       break
     }
   } catch (e: any) {
-    console.error('[voice/chat] groq error:', e?.message || e)
+    const errStr = String(e?.message || e)
-    const msg = 'Что-то сломалось.'
+    console.error('[voice/chat] groq error:', errStr)
-    emitVoice('error', agent, msg)
+
-    return NextResponse.json({ error: 'llm_failed', detail: String(e?.message || e), text: msg }, { status: 502 })
+    // tool_use_failed: модель неправильно сформировала tool call — повторить без tools
+    if (errStr.includes('tool_use_failed') || errStr.includes('Failed to call a function')) {
+      try {
+        const c2 = client()
+        const fallback = await c2.chat.completions.create({
+          model: MODEL,
+          max_tokens: MAX_TOKENS,
+          messages: apiMessages.slice(0, historyStartLen + 1),
+        })
+        finalText = fallback.choices[0]?.message?.content || ''
+        console.log('[voice/chat] tool_use_failed fallback ok')
+      } catch (e2) {
+        console.error('[voice/chat] fallback failed:', e2)
+        finalText = 'Не удалось выполнить запрос.'
+      }
+    } else {
+      const msg = 'Что-то сломалось.'
+      emitVoice('error', agent, msg)
+      return NextResponse.json({ error: 'llm_failed', detail: errStr, text: msg }, { status: 502 })
+    }
   }
 
   if (!finalText.trim()) {