fix: relay pins G1/G2, OTA CCCD+retry, single version source

- Relay pins: G39→G1, G38→G2
- BUNDLED_FIRMWARE_VERSION → SylDaVersions.SERVER (version.txt)
- OTA: explicit CCCD descriptor write for Android 13+
- OTA: start packet retry (previously no retry, blocked by pending CCCD)
- OTA: firmware path device-mode-aware (server/client subdirs)
- Removed stale root firmware.bin, flashMethodGroup, dialog_overwrite_confirm
- PrefsHelper: serverUUID/clientUUID persistence

scripts/ble_client.py

@@ -0,0 +1,87 @@
+#!/usr/bin/env python3
+"""BLE client for SylDa_Server — send color commands from laptop."""
+
+import asyncio
+import sys
+from bleak import BleakScanner, BleakClient
+
+SERVICE_UUID = "0000abcd-0000-1000-8000-00805f9b34fb"
+CHAR_UUID    = "0000abce-0000-1000-8000-00805f9b34fb"
+SERVER_NAME  = "SylDa_Server"
+
+COLORS = {
+    "r": ("red", b"\x00"),
+    "g": ("green", b"\x01"),
+    "y": ("yellow", b"\x02"),
+    "o": ("orange", b"\x03"),
+    "b": ("blue", b"\x04"),
+}
+
+
+async def find_server():
+    print(f"Scanning for {SERVER_NAME}...")
+    device = await BleakScanner.find_device_by_name(SERVER_NAME, timeout=10)
+    if not device:
+        print("Not found.")
+        return None
+    print(f"Found: {device.name} ({device.address})")
+    return device
+
+
+async def send_color(client, data):
+    await client.write_gatt_char(CHAR_UUID, data, response=True)
+    print(f"Sent: {COLORS[[k for k, v in COLORS.items() if v[1] == data][0]][0]}")
+
+
+def show_menu():
+    print("\n┌─────────────────────┐")
+    print("│ r = red             │")
+    print("│ g = green           │")
+    print("│ y = yellow          │")
+    print("│ o = orange          │")
+    print("│ b = blue            │")
+    print("│ q = quit            │")
+    print("└─────────────────────┘")
+
+
+async def connect_handler(client):
+    print(f"Connected: {client.is_connected}")
+
+
+async def disconnect_handler(client):
+    print("Disconnected from server.")
+
+
+async def main():
+    device = await find_server()
+    if not device:
+        return
+
+    async with BleakClient(
+        device,
+        disconnected_callback=disconnect_handler,
+        timeout=10,
+    ) as client:
+        await connect_handler(client)
+
+        while True:
+            try:
+                show_menu()
+                cmd = await asyncio.get_event_loop().run_in_executor(
+                    None, lambda: input("> ").strip().lower()
+                )
+            except (EOFError, KeyboardInterrupt):
+                break
+
+            if cmd == "q":
+                break
+            elif cmd in COLORS:
+                await send_color(client, COLORS[cmd][1])
+            else:
+                print(f"Unknown: {cmd}")
+
+    print("Bye.")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())