fix(homeassistant): storage reads used of total with its percentage, and an OS update is said to wait on a reboot (#6753, #6754)

The tile shows Home Assistant's own used figure beside the total, so it matches
Home Assistant's storage page. An OS update doesn't reboot the machine: Supervisor
writes the image, reports the new version and raises a repair asking for a reboot.
The confirmation, schedule warning, MCP docs and plugin docs now say so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugins/homeassistant/schedule.py

@@ -1,7 +1,7 @@
 # plugins/homeassistant/schedule.py
 """Installing what's waiting at a weekly slot: one at a time through the same path
 as the page's Install, each after its own confirmed backup. Add-ons go first and
-the OS last, as it reboots the machine. The first failure ends the slot, leaving the
+the OS last, as it waits on a reboot. The first failure ends the slot, leaving the
 rest for someone to look at. Everything is on the rows, so a restart of Steward or
 of Home Assistant only delays the next step."""
 from __future__ import annotations