feat: add Q7 dock state enums

[akj]

Q7 dock activity and dust collection are exposed as raw integers. This follow-up to #921 gives consumers named idle and collecting_dust states using the Q7 M5+ capture evidence: station_act=3 and dust_action=1 during emptying, both zero when idle.

Both fields use RoborockEnum, preserving numeric serialization for known states. Unrecognized codes resolve to unknown = -1, and missing values remain None.

Tests cover known and unknown codes, missing values, both key naming styles, numeric serialization, and the mocked Q7 query path.

CI passed: all 1,033 tests on Python 3.11 and 3.14, lint, commit-message validation, package build, and semantic-release checks.

The state values come from previously captured hardware runs. No new live device test was performed for this change.

[allenporter]

@akj nice improvement, thank you!