Update xpower-flow-card.js

## v1.3.44

- Card style option: `xPower` (default) or `Home Assistant` (follows the theme's card background, shadow, border and radius)
- Self-sufficiency badge (leaf + percentage) is always visible
- Self-sufficiency frame can be turned off (`autarky_frame: false`); the badge stays visible
- Flow speed is now proportional to each line's power by default (`flow_speed: proportional`); `synced` keeps the previous phase-locked relay
- Language defaults to the Home Assistant language (`language` empty = auto)
- Editor labels update immediately when the language is changed

Author: BTNBx