Ecovacs: vacuum.clean_area starts brushes/suction but robot never moves (DEEBOT T8 AIVI)

### The problem

Calling `vacuum.clean_area` with a `cleaning_area_id` (HA area, resolved via the area selector to a room on the robot's map) is accepted without any error - the robot's brushes and suction turn on, and the official Ecovacs app even shows the correct zone highlighted as the active cleaning target - but the robot never actually drives anywhere. `sensor._area_cleaned` stays at 0 and `sensor._cleaning_duration` stays at ~0 for the whole run (it just sits at the dock with brushes spinning, then the automation/timeout eventually calls `return_to_base` and it docks again having cleaned nothing).

Starting a clean for the exact same room from the official Ecovacs app works completely normally (robot drives there and cleans as expected).

Reproduced with multiple different rooms - not specific to one room/segment, and not specific to passing multiple room IDs in one call (a single room alone reproduces it).

No errors show up in the HA logs, even after setting `homeassistant.components.ecovacs` and `deebot_client` loggers to debug via `logger.set_level` - `system_log`/the Repairs log viewer only ever surfaces WARNING and above regardless of the configured logger level, so I could not capture protocol-level detail this way. If there is a better way to get deebot_client debug output written somewhere retrievable, I am happy to try again and attach it.

Device: Ecovacs DEEBOT T8 AIVI (older/legacy protocol generation).

### What version of Home Assistant Core has the issue?

core-2026.9.1

### What was the last working version of Home Assistant Core?

_No response_

### What type of installation are you running?

Home Assistant OS

### Integration causing the issue

Ecovacs

### Link to integration documentation on our website

https://www.home-assistant.io/integrations/ecovacs/

### Diagnostics information

_No response_

### Example YAML snippet

```yaml
service: vacuum.clean_area
target:
entity_id: vacuum.pomichnik
data:
cleaning_area_id:
- koridor
```

### Anything in the logs that might be useful for us?

```txt

```

### Additional information

_No response_