feat(voice): server-side LLM/STT — porting Python satellite into tablet

Шаг 1 миграции голосового стека из home-voice-assistant в сам tablet:

- /api/voice/chat — Claude Haiku 4.5 с tool-loop (max 4 раунда), prompt
  caching на system + старой истории, история в /data/voice-history/.
  Эмитит command/response/error в voice-bus → орб моргает как раньше.
- /api/voice/stt — Groq whisper-large-v3-turbo, multipart или raw audio.
- lib/voice-text.ts — порт clean_for_speech (без pymorphy3, время в
  именительном падеже) и strip_fillers + RESET_PATTERNS.
- lib/voice-executors.ts — tool executors через loopback fetch на
  существующие /api/voice/tools/* и /api/voice/timer.
- Поддержка ANTHROPIC_PROXY/GROQ_PROXY (fallback на HTTPS_PROXY).

После деплоя нужны GROQ_API_KEY и ANTHROPIC_API_KEY в tablet.env.
Шаги 2 (push-to-talk в браузере) и 3 (wake-word) — отдельно.

app/api/voice/stt/route.ts

@@ -0,0 +1,71 @@
+export const dynamic = 'force-dynamic'
+export const runtime = 'nodejs'
+
+import { NextResponse } from 'next/server'
+import Groq from 'groq-sdk'
+import { HttpsProxyAgent } from 'https-proxy-agent'
+import { toFile } from 'groq-sdk/uploads'
+
+const STT_MODEL = process.env.GROQ_STT_MODEL || 'whisper-large-v3-turbo'
+
+let _client: Groq | null = null
+function client(): Groq {
+  if (_client) return _client
+  const apiKey = process.env.GROQ_API_KEY
+  if (!apiKey) throw new Error('GROQ_API_KEY not set')
+  const proxy = process.env.GROQ_PROXY || process.env.HTTPS_PROXY || ''
+  const httpAgent = proxy ? new HttpsProxyAgent(proxy) : undefined
+  _client = new Groq({ apiKey, httpAgent })
+  return _client
+}
+
+// Принимает либо multipart/form-data с полем "file",
+// либо raw audio в теле (Content-Type: audio/* — например audio/webm).
+// Возвращает {text: string}.
+export async function POST(req: Request) {
+  let audio: { name: string; data: Buffer; mime: string }
+
+  const ct = req.headers.get('content-type') || ''
+
+  try {
+    if (ct.startsWith('multipart/form-data')) {
+      const fd = await req.formData()
+      const file = fd.get('file')
+      if (!(file instanceof Blob)) {
+        return NextResponse.json({ error: 'file field required' }, { status: 400 })
+      }
+      const ab = await file.arrayBuffer()
+      audio = {
+        name: (file as any).name || 'audio.webm',
+        data: Buffer.from(ab),
+        mime: file.type || 'audio/webm',
+      }
+    } else {
+      const ab = await req.arrayBuffer()
+      if (!ab.byteLength) {
+        return NextResponse.json({ error: 'empty body' }, { status: 400 })
+      }
+      audio = {
+        name: 'audio.webm',
+        data: Buffer.from(ab),
+        mime: ct || 'audio/webm',
+      }
+    }
+  } catch (e) {
+    return NextResponse.json({ error: 'failed_to_read_body' }, { status: 400 })
+  }
+
+  try {
+    const file = await toFile(audio.data, audio.name, { type: audio.mime })
+    const result = await client().audio.transcriptions.create({
+      file,
+      model: STT_MODEL,
+      language: 'ru',
+    })
+    const text = (result as any).text || ''
+    return NextResponse.json({ text })
+  } catch (e: any) {
+    console.error('[voice/stt] groq error:', e?.message || e)
+    return NextResponse.json({ error: 'stt_failed', detail: String(e?.message || e) }, { status: 502 })
+  }
+}