hass.windy.lan: resolve health snapshot issues (W1N-70..76) and document findings

- Add tianqi weather recorder patch notes (W1N-75: _unrecorded_attributes)
- Document Bluetooth hci0 RTL8821CS instability (W1N-74) and eMMC lifetime
  10% (W1N-76) as known issues
- Rewrite runbook known-issues section: all snapshot items resolved; link
  hosts doc for the two remaining known issues

runbooks/home-assistant-maintenance.md

@@ -190,16 +190,20 @@ installed CLI** (2026-08-13): backups are inspected with `ha backups info
 <slug>` (a slug is required) and `host` has no `update` subcommand. Trust the
 server CLI (`ha <cmd> --help`) over the docs.
 
-## Known issues on hass.windy.lan (observed 2026-08-13)
+## Known issues on hass.windy.lan (2026-08-13)
 
-From the health snapshot — follow-ups are optional, no action taken:
+All items from the original 2026-08-13 health snapshot were resolved same day
+(W1N-70/71/72/73/74/75/76): OTBR and the duplicate SSH add-on uninstalled, all
+resolution-center issues cleared (`ha resolution info` → empty), full backup
+`pre-maintenance-20260813` (slug `411a4ba5`) taken. Remaining known issues
+(documented in [hosts/hass.windy.lan.md](../hosts/hass.windy.lan.md)):
 
-- **2 add-ons in `state: error`**: `core_openthread_border_router`,
-  `a0d7b954_ssh` (duplicate Advanced SSH & Web Terminal install).
-- **`ha resolution info` issues**: `systemd_unit_failed`
-  (`systemd-vconsole-setup.service`), `no_current_backup`, 2×
-  `corrupt_repository` (store `d5369777`, `a0d7b954`).
-- `host info` reports `disk_life_time: 10` (disk lifetime warning threshold).
+- **Bluetooth hci0 instability (RTL8821CS)**: `bluetooth_auto_recovery`
+  power-reset times out every ~2 min; kernel `hci0 hardware error`. No BLE
+  entities exist, so no user impact. HAOS image ships `x88-bt-hci-recovery`
+  workaround units.
+- `host info` reports `disk_life_time: 10` (boot eMMC ~10% life left) —
+  monitor on each snapshot; plan disk replacement / data-disk migration.
 
 ## Pass criteria