HA bridge: driver names with spaces/commas produce illegal MQTT discovery topics — sensors silently dropped #960

Summary

The Home Assistant bridge builds MQTT discovery topics from the raw configured driver name. A driver named with characters MQTT/HA forbid in topics — my Easee is name: Laddare, Garage (comma, space) — produces discovery topics HA rejects outright, and every sensor published under that name is silently absent from HA:

WARNING [homeassistant.components.mqtt.discovery] Received message on illegal discovery topic
'homeassistant/sensor/forty_two_watts/Laddare, Garage_ev_current_a/config'.
The topic contains non allowed characters.

Lost on this site: ev_current_a, ev_voltage_v, ev_lifetime_kwh, ev_dynamic_current_a — the per-driver EV detail. The core power sensors are unaffected because their object ids don't embed the driver name.

Where

The bridge composes the discovery object id as <driver name>_<sensor>. HA's discovery topics allow only [a-zA-Z0-9_-] in the object id segment; the driver name: is free-form YAML and reasonably contains spaces, commas, or Unicode ("Laddare" could as easily be "Värmepump, källaren").

Suggested fix

Slugify the driver-name segment when composing discovery object ids (lowercase, [^a-z0-9_-] → _, collapse repeats), keeping the human-readable name in the discovery payload's name/device fields where it belongs. The unique_id should follow the same slug so entities stay stable across renames of the display name — or better, key it on the driver's stable identity rather than the YAML name, consistent with the persistent-state-identity invariant.

Live repro available on my site (v1.15.x-era gateway, current stable drivers).

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