hide_battery_low option doesn't hide battery-low sensors created for devices with a native battery source

[Mikey887]

Describe the bug
The global hide_battery_low option (Settings → Devices & Services → Battery Notes → Configure) only hides the self-estimated binary_sensor._battery_plus_low entities — the ones Battery Notes creates when a device has no native battery sensor. It does not hide the plain binary_sensor._battery_low entities that Battery Notes creates when wrapping a device's existing native battery sensor (linked via the battery_notes.entity_id registry option).

To Reproduce

1. Enable hide_battery_low: true in Battery Notes options.
2. Look at a device that already has its own native battery sensor (e.g. a Hue motion sensor, a Zigbee switch/remote, an Aqara contact sensor) — Battery Notes creates binary_sensor._battery_low for it.
3. Observe that entity remains visible (hidden_by: null) despite the option being on, while binary_sensor._battery_plus_low entities (self-estimated, no native source) on other devices are correctly hidden (hidden_by: integration).

Expected behavior
hide_battery_low: true should hide all battery-low binary sensors Battery Notes creates, regardless of whether the underlying battery percentage comes from Battery Notes' own estimate or from the device's native sensor.

Environment

• Battery Notes version: 3.4.8
• Home Assistant Core: 2026.7.2
• Confirmed across ~26 affected entities spanning ZHA, Hue, Ring, Aqara, and other platforms — all sharing the same pattern (native-linked *_battery_low, no + in the name).

Workaround
Manually setting hidden: true in the entity registry for each affected entity works, but doesn't scale — every new device with a native battery sensor needs the same manual fix.

[andrew-codechimp]

I'm able to reproduce this, there are conditions when to show a low and these slipped through.
I'll work on a fix.