ap: switch 5GHz driver to out-of-tree morrownr/rtw89 for USB3 support

The in-kernel rtw89_8852bu on this Ubuntu kernel base predates mainline's
USB2->3 auto-switch for this chip, permanently capping the AP dongle at
USB2/480M. morrownr/rtw89 (dkms) has that switch. ap/rtw89.conf now
blacklists the in-kernel rtw89 modules and tunes the replacement
(disable_ps_mode + switch_usb_mode); ap/install-rtw89-driver.sh builds
and installs it, pinned to a specific upstream commit, kept separate
from deploy.sh since a dkms rebuild is too slow to run on every deploy.

Verified live: negotiates USB3/5000M on a dedicated USB3 controller
(480M on a USB2-only one, as expected), AP recovered via hostapd's
Restart=always + van-ap-watchdog with no manual intervention. Hit and
documented one real gotcha along the way: in-kernel rtw89_core refused
to unload while its own dependents (rtw89_8852b, rtw89_8852b_common)
were still loaded, which blocked the new module with a duplicate-symbol
error until all in-kernel modules were removed first.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YJfEELeh3ercpRBp8yYrYS

ap/rtw89.conf

@@ -1 +1,48 @@
-options rtw89_core disable_ps_mode=Y
+# 5GHz AP dongle (Realtek RTL8852BU). Since 2026-08-23 this uses the out-of-tree
+# morrownr/rtw89 driver (dkms package "rtw89", modules suffixed _git) instead of the
+# in-kernel rtw89_8852bu — the in-kernel driver on this Ubuntu kernel base predates
+# mainline's USB2->3 auto-switch, so the dongle was permanently capped at USB2/480M.
+# Install: https://github.com/morrownr/rtw89 (`sudo dkms install`, `sudo make
+# install_fw`). This file both tunes the driver and blacklists the in-kernel modules
+# so udev picks the out-of-tree ones on (re)enumeration.
+options rtw89_core_git disable_ps_mode=Y
+options rtw89_usb_git switch_usb_mode=y
+
+# Blacklist the in-kernel rtw89 drivers.
+blacklist rtw89_8851bu
+blacklist rtw89_8851be
+blacklist rtw89_8851b
+blacklist rtw89_8852au
+blacklist rtw89_8852ae
+blacklist rtw89_8852a
+blacklist rtw89_8852b_common
+blacklist rtw89_8852bu
+blacklist rtw89_8852be
+blacklist rtw89_8852b
+blacklist rtw89_8852bte
+blacklist rtw89_8852bt
+blacklist rtw89_8852cu
+blacklist rtw89_8852ce
+blacklist rtw89_8852c
+blacklist rtw89_8922au
+blacklist rtw89_8922ae
+blacklist rtw89_8922a
+blacklist rtw89_8922de
+blacklist rtw89_8922d
+blacklist rtw89_core
+blacklist rtw89_usb
+blacklist rtw89_pci
+
+# Blacklist Larry Finger's out-of-tree rtw89 driver too, in case it's ever installed.
+blacklist rtw89core
+blacklist rtw89pci
+blacklist rtw_8851b
+blacklist rtw_8851be
+blacklist rtw_8852a
+blacklist rtw_8852ae
+blacklist rtw_8852b
+blacklist rtw_8852be
+blacklist rtw_8852c
+blacklist rtw_8852ce
+blacklist rtw_8922a
+blacklist rtw_8922ae