[Device Support] Add mop_mode 300 and water_box_mode 235 for "Vacuum then Mop" (Saros 20)

[Puncher4444]

Describe the bug

When setting the cleaning mode to "Vacuum then Mop" in the Roborock App, python-roborock fails to map mop_mode: 300 and water_box_mode: 235. This causes upstream consumers (such as Home Assistant) to display an Unknown state for the mop mode entities.

Roborock Model

Roborock Saros 20
Firmware: 02.55.44

App Version

Roborock App (Latest)

Python-roborock Version

Latest (python-roborock version shipped with Home Assistant Core)

Expected Behavior

mop_mode: 300 should be recognized as VACUUM_THEN_MOP (or equivalent enum state) instead of raising an unmapped enum warning/falling back to unknown.

Diagnostics / Logs

Here is the decoded payload from GET_STATUS while the device is set to "Vacuum then Mop":

{
  "msg_ver": 2,
  "msg_seq": 3205,
  "state": 8,
  "battery": 85,
  "clean_time": 564,
  "clean_area": 7582500,
  "error_code": 0,
  "map_present": 1,
  "in_cleaning": 0,
  "in_returning": 0,
  "in_fresh_state": 1,
  "lab_status": 3,
  "water_box_status": 1,
  "back_type": -1,
  "wash_phase": 0,
  "wash_ready": 1,
  "wash_status": 512,
  "fan_power": 102,
  "dnd_enabled": 0,
  "map_status": 3,
  "is_locating": 0,
  "lock_status": 0,
  "water_box_mode": 235,
  "distance_off": 0,
  "water_box_carriage_status": 1,
  "mop_forbidden_enable": 1,
  "camera_status": 8613,
  "is_exploring": 0,
  "home_sec_status": 0,
  "home_sec_enable_password": 1,
  "monitor_status": 0,
  "adbumper_status": [0, 0, 0],
  "water_shortage_status": 0,
  "dock_type": 27,
  "dust_collection_status": 0,
  "auto_dust_collection": 1,
  "avoid_count": 0,
  "mop_mode": 300,
  "debug_mode": 0,
  "in_warmup": 0,
  "collision_avoid_status": 1,
  "switch_map_mode": 0,
  "dock_error_status": 0,
  "charge_status": 1,
  "unsave_map_reason": 0,
  "unsave_map_flag": 0,
  "dry_status": 1,
  "rdt": 8280,
  "clean_percent": 0,
  "extra_time": 0,
  "rss": 2,
  "dss": 2216,
  "common_status": 2,
  "last_clean_t": 1788529011,
  "replenish_mode": 0,
  "repeat": 1,
  "kct": 0,
  "subdivision_sets": 0,
  "cleaning_info": {
    "target_segment_id": -1,
    "segment_id": -1,
    "fan_power": 105,
    "water_box_status": 200,
    "mop_mode": 300
  },
  "exit_dock": 0,
  "seq_type": 0,
  "pet_reminding": 0,
  "sub_error_code": 0,
  "sub_zone": -1
}