Add device support for Samsung AirDresser DA_DF_A51_20_COMMON (#162)

This board reports no oneUiVersion and no modelNum token any existing
family routed on, so it fell back to the global unknown-device CAPABILITIES
set -- exposing only power/child-lock/start-stop-pause/delay/energy/machine
state, with /course/vs/0, /diagnosis/vs/0, and /washer/vs/0 all unbound and
no course/mode select at all (the actual reported gap).

Every one of those resources turns out to already be handled by the shared
laundry machinery: /diagnosis/vs/0 reuses dishwasher.DIAGNOSIS, and
/course/vs/0's cycle select works unmodified through laundry.cycle_options'
existing supportedOptions fallback (this board has no /wm/editcourse/vs/0
at all, so editCourseList never populates). /washer/vs/0 gets a new minimal
AIR_DRESSER_SETTINGS capability (wrinkle_prevent only) rather than reusing
dryer.DRYER_SETTINGS wholesale, since this device never reports
dryLevel/dryTime/dryerType at all and binding them would ship three
permanently-unavailable sensors.

Course codes aren't identified yet (no code->name mapping was reported), so
they render as their raw codes until named in translations, same as
dryer.py's precedent for unidentified codes.

README.md

@@ -48,6 +48,7 @@ Your state stays on your LAN: HA talks to the appliance over a direct DTLS sessi
 | Washer | `by_type/washer.py` |
 | Water purifier | `by_type/water_purifier.py` |
 | Vacuum clean/auto-empty station | `by_type/vacuum_station.py` |
+| Air dresser | `by_type/air_dresser.py` |
 
 Each registry composes shared and family-specific `Capability` objects from `registry/capabilities/`; those modules document the individual resources/entities in more depth than a README table can stay current with.