fix: surface waterbox attachment status

[dacrypt]

Summary

• surface the official X20+ waterbox-status (siid 4 piid 6) in cloud status output
• show water box attachment state in rich CLI status/full/report output and Mission Control status tags
• bump version to 0.6.5 and record the shipped change/backlog follow-up

Why

Users can already inspect raw vacuum-extend properties, but they cannot quickly tell whether the mop water box is attached during setup or mopping diagnostics.

Research basis

• local backlog/spec notes already mapped siid 4 piid 6 to waterbox-status
• OpenHAB's xiaomi.vacuum.c102gl MIoT database exposes waterbox-status as 0 = No, 1 = Yes
• adjacent community docs/issues confirmed this is a real X20+ property worth surfacing, with low implementation risk

Tests

• added failing-first coverage for cloud status decoding of waterbox-status
• added formatter coverage for full status rendering
• added Mission Control dashboard HTML coverage for the surfaced status
• ran:
  • .venv/bin/python -m pytest tests/ -v
  • .venv/bin/ruff check src/ tests/
  • .venv/bin/ruff format --check src/ tests/
  • .venv/bin/mypy src/xiao/

Risk

Low: read-only property surfacing plus UI copy; no command semantics changed.