Issue vehicle charging commands (start, stop, amps, limit) through the Tesla Fleet API

Steps

1. Obtain a partner OAuth token and a signed vehicle command capability by completing Tesla's Fleet API application registration and domain verification.
2. Wake the vehicle if needed and call the charging endpoints under /api/1/vehicles/{vehicle_tag}/command/ — charge_start and charge_stop to begin/end an active charging session.
3. Call set_charging_amps with a target amperage to adjust the live charge rate, and set_charge_limit / set_charge_limit_soc to adjust the target state-of-charge limit.
4. Use charge_port_door_open / charge_port_door_close if the integration also needs to control the physical charge port for automated depot charging.
5. Poll vehicle_data (charge_state) after issuing a command to confirm the vehicle actually applied it, since command endpoints acknowledge receipt, not guaranteed physical effect.