Add location reporting as a device_tracker

[jlclemmons]

Adds optional location reporting: a GeoClue2 client that posts fixes to the existing update_location webhook, which makes Home Assistant create a device_tracker for the machine so it can be used for presence and zones. This is the "roaming laptops" direction from the README's to-do list, though it does not attempt the remote/local instance part.

• Off unless a location section sets "enabled": true.
• No new dependencies — dbus_next is already required for notifications.
• Existing configuration files keep working: the section and every option in it are defaulted, so a config written before this change still validates.

How well it works depends on the machine

Worth being upfront, since the answer is very different per device:

• A machine with a GNSS receiver (a Linux phone, or a laptop with a WWAN module exposing GPS) gets fixes accurate to a few metres.
• A typical desktop or laptop has no GNSS, so GeoClue falls back to a wifi lookup — usually tens to hundreds of metres, and dependent on the surrounding access points being in the database it queries. For a machine that never moves that may be enough for a home/away zone, but it can be wrong by a street, and it is not a replacement for a phone's tracker.

max_accuracy defaults to 500m for that reason: it rejects cell-tower-grade fixes without discarding the wifi positioning a desktop depends on. Devices with GNSS can set it far tighter.

Design notes

Two things that are less obvious than they look, both documented in the commit and the README:

• The heartbeat re-reads GeoClue rather than resending the last payload. update_location carries no timestamp, so Home Assistant stamps whatever arrives as current. Replaying a cached fix therefore asserts a stale position indefinitely while looking freshly updated. Re-reading costs nothing, since GeoClue serves the last fix its source produced rather than powering up a receiver to answer. It exists at all because DistanceThreshold means a stationary device stops emitting entirely, which is when a lost device most needs to report.
• Fixes are dropped when they are worse than max_accuracy or older than max_age, and nothing is sent when there is no usable fix. RequestedAccuracyLevel = EXACT is only a hint about which source GeoClue may use, not a floor on what it delivers, so coarse fixes still arrive and would otherwise be plotted as the device's position. A tracker that goes stale is honest; one that is confidently in the wrong place is not.

Similarly, distance_threshold defaults to a fairly tight 30m because the last emitted fix can be a threshold's worth of distance behind where the device actually came to rest.

Testing

• Running on a FuriPhone FLX1s+ (FuriOS/Phosh, geoclue 2.7.1 with the hybris GNSS source) reporting to Home Assistant 2026.7 over HTTPS, currently producing 3m fixes.
• halinuxcompanion/test_location.py adds 15 tests covering config defaults and the reporting rules, including that the heartbeat reports the current fix rather than a stale one. They drive the event loop directly instead of using a pytest-asyncio marker, since that plugin is in requirements.txt but not in the tox environment, where a marked test would silently skip.
• Full suite passes (21 tests), and pycodestyle --max-line-length=120 is clean across the package.

Happy to adjust any of the defaults, or to gate the feature differently, if you would rather it were shaped another way.

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Developed with AI assistance (Claude); the commits carry a Co-Authored-By trailer to that effect. Everything above has been reviewed and tested on real hardware.