USB wording: a USB 2.0 type-A plug on the way; hubs are fine

Guide, README, quick start and flashing hints no longer say 'no hub' or 'directly to the laptop'; the requirement is a USB 2.0 type-A plug between box and computer (USB-C only is the failing case).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

kota_tech/flash/runner.py

@@ -26,7 +26,7 @@ HINTS = [
      "The box did not enter flashing mode by itself. Open the case, hold the BOOT button, press and release RESET, "
      "release BOOT, then press Start again."),
     (re.compile(r"device reports readiness to read but returned no data|The port disappeared|device disconnected", re.I),
-     "The USB connection dropped. Use a short data-capable USB cable directly on the laptop (no hub) and try again."),
+     "The USB connection dropped. Use a data-capable cable with a USB 2.0 type-A plug on the way to the laptop (not USB-C only) and try again."),
     (re.compile(r"Invalid head of packet|timed out", re.I),
      "Communication errors. Try another USB cable or port."),
 ]