feat(api): parallel group sends and batch identify

- asyncio.gather for group brightness and driver-config Wi-Fi pushes
- Batch identify envelope for group members

Co-authored-by: Cursor <cursoragent@cursor.com>

src/controllers/device.py

@@ -167,6 +167,107 @@ async def _identify_send_off_after_delay(sender, transport, wifi_ip, dev_id, nam
         pass
 
 
+async def send_identify_to_device(dev_id: str) -> tuple[int, str]:
+    """
+    Send the same identify blink as ``POST /devices/<id>/identify``.
+
+    Returns ``(http_status, "")`` on success, or ``(status, error_message)`` on failure
+    (status matches the single-device route).
+    """
+    dev = devices.read(dev_id)
+    if not dev:
+        return 404, "Device not found"
+    sender = get_current_sender()
+    if not sender:
+        return 503, "Transport not configured"
+    name = str(dev.get("name") or "").strip()
+    if not name:
+        return 400, "Device must have a name to identify"
+
+    transport = dev.get("transport") or "espnow"
+    wifi_ip = None
+    if transport == "wifi":
+        wifi_ip = dev.get("address")
+        if not wifi_ip:
+            return 400, "Device has no IP address"
+
+    try:
+        msg = _compact_v1_json(
+            presets={_IDENTIFY_PRESET_KEY: dict(_IDENTIFY_DRIVER_PRESET)},
+            select={name: [_IDENTIFY_PRESET_KEY]},
+        )
+        if transport == "wifi":
+            ok = await send_json_line_to_ip(wifi_ip, msg)
+            if not ok:
+                return 503, "Wi-Fi driver not connected"
+        else:
+            await sender.send(msg, addr=dev_id)
+
+        asyncio.create_task(
+            _identify_send_off_after_delay(sender, transport, wifi_ip, dev_id, name)
+        )
+    except Exception as e:
+        return 503, str(e)
+    return 200, ""
+
+
+async def send_identify_to_group_devices(macs: list[str]) -> tuple[int, list[dict]]:
+    """
+    Identify every listed registry MAC in one delivery round: merged ``select`` and a single
+    ESP-NOW split envelope when multiple peers share the serial bridge (avoids per-device
+    ``SerialSender`` lock serialisation). Wi-Fi peers are sent in parallel as in
+    ``deliver_json_messages``.
+    """
+    from util.driver_delivery import deliver_json_messages
+
+    errors: list[dict] = []
+    sender = get_current_sender()
+    if not sender:
+        return 0, [{"mac": "*", "error": "Transport not configured"}]
+
+    merged_select: dict[str, list[str]] = {}
+    valid_macs: list[str] = []
+    for dev_id in macs:
+        dev = devices.read(dev_id)
+        if not dev:
+            errors.append({"mac": dev_id, "error": "Device not found"})
+            continue
+        name = str(dev.get("name") or "").strip()
+        if not name:
+            errors.append({"mac": dev_id, "error": "Device must have a name to identify"})
+            continue
+        transport = (dev.get("transport") or "espnow").strip().lower()
+        if transport == "wifi":
+            if not dev.get("address"):
+                errors.append({"mac": dev_id, "error": "Device has no IP address"})
+                continue
+        merged_select[name] = [_IDENTIFY_PRESET_KEY]
+        valid_macs.append(dev_id)
+
+    if not merged_select:
+        return 0, errors
+
+    try:
+        msg = _compact_v1_json(
+            presets={_IDENTIFY_PRESET_KEY: dict(_IDENTIFY_DRIVER_PRESET)},
+            select=merged_select,
+        )
+        await deliver_json_messages(sender, [msg], valid_macs, devices, delay_s=0)
+    except Exception as e:
+        return 0, errors + [{"mac": "*", "error": str(e)}]
+
+    for dev_id in valid_macs:
+        dev = devices.read(dev_id) or {}
+        name = str(dev.get("name") or "").strip()
+        transport = (dev.get("transport") or "espnow").strip().lower()
+        wifi_ip = dev.get("address") if transport == "wifi" else None
+        asyncio.create_task(
+            _identify_send_off_after_delay(sender, transport, wifi_ip, dev_id, name)
+        )
+
+    return len(valid_macs), errors
+
+
 @controller.get("")
 async def list_devices(request):
     """List all devices (includes ``connected`` for live Wi-Fi WebSocket presence)."""
@@ -341,53 +442,12 @@ async def identify_device(request, id):
     this device name — same combined shape as profile sends the driver already accepts over TCP
     / ESP-NOW. No ``save``. After ``IDENTIFY_OFF_DELAY_S``, a background task selects ``off``.
     """
-    dev = devices.read(id)
-    if not dev:
-        return json.dumps({"error": "Device not found"}), 404, {
+    status, err = await send_identify_to_device(id)
+    if status == 200:
+        return json.dumps({"message": "Identify sent"}), 200, {
             "Content-Type": "application/json",
         }
-    sender = get_current_sender()
-    if not sender:
-        return json.dumps({"error": "Transport not configured"}), 503, {
-            "Content-Type": "application/json",
-        }
-    name = str(dev.get("name") or "").strip()
-    if not name:
-        return json.dumps({"error": "Device must have a name to identify"}), 400, {
-            "Content-Type": "application/json",
-        }
-
-    transport = dev.get("transport") or "espnow"
-    wifi_ip = None
-    if transport == "wifi":
-        wifi_ip = dev.get("address")
-        if not wifi_ip:
-            return json.dumps({"error": "Device has no IP address"}), 400, {
-                "Content-Type": "application/json",
-            }
-
-    try:
-        msg = _compact_v1_json(
-            presets={_IDENTIFY_PRESET_KEY: dict(_IDENTIFY_DRIVER_PRESET)},
-            select={name: [_IDENTIFY_PRESET_KEY]},
-        )
-        if transport == "wifi":
-            ok = await send_json_line_to_ip(wifi_ip, msg)
-            if not ok:
-                return json.dumps({"error": "Wi-Fi driver not connected"}), 503, {
-                    "Content-Type": "application/json",
-                }
-        else:
-            await sender.send(msg, addr=id)
-
-        asyncio.create_task(
-            _identify_send_off_after_delay(sender, transport, wifi_ip, id, name)
-        )
-    except Exception as e:
-        return json.dumps({"error": str(e)}), 503, {"Content-Type": "application/json"}
-    return json.dumps({"message": "Identify sent"}), 200, {
-        "Content-Type": "application/json",
-    }
+    return json.dumps({"error": err}), status, {"Content-Type": "application/json"}
 
 
 @controller.post("/<id>/brightness")