Expose Bosch RM230Z weekly schedule

[MaxRink]

Summary

• expose standard Zigbee thermostat weekly schedule controls for Bosch BTH-RM230Z (Room thermostat II 230V)
• keep the shared Bosch RM thermostat helper opt-in so the battery RM model remains unchanged
• use a Bosch-specific snake_case weekly schedule expose while keeping the toZigbee converter compatible with existing camelCase payloads
• add regression coverage for RM230Z schedule exposure and configure-time schedule capability reads

Context

The Bosch RM230Z manual describes automatic room control through a schedule. The existing converter already exposes the Bosch private operating_mode value schedule, but did not expose the standard ZCL weekly schedule payloads needed to inspect or write the actual schedule.

Related prior work in #9662 covered other private Bosch thermostat attributes; I did not find schedule support implemented there.

The generic thermostat weekly schedule expose currently uses camelCase properties that fail the repository expose naming check, so this PR leaves the shared helper untouched and adds an opt-in Bosch expose using transition_time and heat_setpoint. The converter accepts both the new snake_case keys and the existing camelCase keys for compatibility.

Validation

• PATH="/opt/homebrew/opt/node@24/bin:$PATH" npx pnpm@10.12.1 exec vitest run test/checks.test.ts test/bosch.test.ts test/toZigbee.test.ts --config ./test/vitest.config.mts
• PATH="/opt/homebrew/opt/node@24/bin:$PATH" npx pnpm@10.12.1 run check
• PATH="/opt/homebrew/opt/node@24/bin:$PATH" npx pnpm@10.12.1 run build
• PATH="/opt/homebrew/opt/node@24/bin:$PATH" npx pnpm@10.12.1 test

Combined live validation on my Home Assistant instance

• Built a combined ZHC override containing this PR together with Make Shelly 2PM cover tilt configurable #12497, Make Bosch RM230Z HA climate modes configurable #12498, Handle named custom raw attribute responses #12509, and Expose SONOFF valve settings as scalar controls #12510, then deployed the compiled files to the Zigbee2MQTT add-on.
• Verified all five live Bosch Room Thermostat II 230V devices expose weekly_schedule via zigbee2mqtt/bridge/devices: Bad Thermostat, Schlafzimmer Thermostat, Arbeitszimmer Thermostat, Wohnzimmer Thermostat Flur, Wohnzimmer Thermostat Küche.
• Verified the retained Home Assistant discovery payloads for all five Bosch climate entities still publish heat-only default modes: ["off", "heat", "auto"].
• Verified the schedule support composes with Make Bosch RM230Z HA climate modes configurable #12498's homeassistant_climate_modes option on the same live devices.

[Koenkk]

Thanks!