chore: bump firmware + faster LLM failover

Bump ESP32_ZACUS to 82759ee (voice-activated two-phase capture, mic
diag). Gateway: drop the local-LLM (granite) timeout 70s -> 8s so a
cold/hung local model fails over to the remote backend fast instead of
stalling the whole turn past the firmware's reply timeout.

tools/zacus-gateway/main.py

@@ -241,10 +241,13 @@ async def _chat_reply(http: httpx.AsyncClient, persona: str, history: list[dict]
     """
     messages = [{"role": "system", "content": persona + _PHONE_STYLE}] + history
     backends = [
-        # 70 s tolerates a ~47 s cold (re)load with margin; the keep-warm task
-        # keeps it ~2 s in normal operation. Total turn (STT ~10 s + this + say
-        # ~2 s) stays under the firmware's 90 s turn_client timeout.
-        ("local", settings.local_chat_url, settings.local_chat_model, 70.0),
+        # 8 s: a healthy warm granite answers in ~2 s, so 8 s gives margin while
+        # failing over FAST when the local server is cold, hung, or deadlocked.
+        # Waiting the full cold-load (~47 s) here would blow the turn budget —
+        # the player hears only the filler and the reply never lands in time.
+        # The keep-warm task is responsible for keeping granite warm; if it is
+        # unreachable we want the remote fallback immediately, not a 70 s stall.
+        ("local", settings.local_chat_url, settings.local_chat_model, 8.0),
         ("ailiance", settings.ailiance_tts_url, settings.ailiance_chat_model, 12.0),
     ]
     last_exc: Exception | None = None