Show charging status for Limitless Pendant in the Omi app

**Problem** When the Limitless Pendant is on the charger, the Omi app doesn’t clearly show that it’s actually charging. The only way to tell is to wait and see if the battery percentage goes up. **Requested behavior** Add a clear charging indicator in the app whenever the pendant is on power, such as: - A lightning-bolt icon on/next to the battery - Text like “Charging (42%)” instead of just “42%” - Or a distinct charging color/state for the battery icon **Why it matters** - Lets users quickly confirm the pendant is seated correctly and getting power - Reduces anxiety about leaving with a dead device - Matches expectations from phones/watches/earbuds that always show a charging state