Assist modal doesn't follow frontend theming

**Home Assistant Android app version(s):** 2025.6.6-full

**Android version(s):** 15

**Device model(s):** Samsung Galaxy S24+

**Home Assistant version:**
Installation method - Home Assistant OS
Core - 2025.7.1
Supervisor - 2025.06.2
Operating System - 15.2
Frontend - 20250702.1

**Last working Home Assistant release (if known):**

**Description of problem, include YAML if issue is related to notifications:**
The theme present in desktop an mobile view via browser for the Assit chat interface is not present when using the companion app. This appears to default to the default home assistant theme.

**Companion App Logs:**

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**Screenshot or video of problem:**

Desktop View:

Mobile View:

Companion App:

**Additional information:**