Update bundled homie_schema.json after SPAN 202609 firmware release

[cayossarian]

Summary

The bundled src/span_panel_simulator/data/homie_schema.json should be updated once SPAN firmware release 202609 ships. The current bundled schema is from firmware spanos2/r202603/05; a snapshot from the live device (spanos3/r202603/06) is saved at docs/Dev/homie_schema_2026-03-14.json for reference.

Why wait

The SPAN API changelog documents fixes coming in 202609 that affect the schema:

• Unit corrections: Circuit active-power and PV nameplate-capacity units will be corrected from kW to W to match actual published values
• New core property: model enum (MAIN_16, MLO_24, MAIN_32, MAIN_40, MLO_48)
• New status field: proximityProven on /api/v2/status
• mDNS model format: _device-info._tcp model TXT record changes from SPAN32 to MAIN_32

Updating the bundled schema now would require a second update when 202609 ships, since the unit metadata will change.

What to do

Once 202609 firmware is available on the panel:

1. Pull the updated schema from the panel's eBus API
2. Save a dated copy under docs/Dev/
3. Verify the unit corrections are present (circuit active-power unit should be W, PV nameplate-capacity unit should be W)
4. Verify the new model property appears under energy.ebus.device.distribution-enclosure.core
5. Run tests to ensure the simulator still passes

Context

The simulator code has already been updated (all three tiers) to publish all schema-defined properties including PCS, new core fields, and 202609 prep fields. Only the bundled schema JSON file itself is deferred.