Pomotroid renders only unstyled "25:00" text on ARM64

[AlohaHenrySCD]

Description

Pomotroid starts successfully on NixOS ARM64(asahi linux) under niri/Wayland, but the frontend is not rendered correctly.
The application window opens and displays only the text:
25:00
in what appears to be the default/system font, centered in the window.
There are no visible styles, timer dial, buttons, background/theme, navigation controls, or other UI elements.

Environment

Pomotroid: v1.7.1
OS: NixOS unstable
Architecture: aarch64-linux
Compositor: niri
Session: Wayland
Node.js: v22.23.2
npm: 10.9.8
Rust: 1.97.1

Pomotroid was built/run from source because the official Linux release does not provide an ARM64 binary.

Steps to reproduce

1. Clone Pomotroid on an ARM64 NixOS system.
2. Install the required dependencies in a Nix development shell, including WebKitGTK 4.1.
3. Run:
   npm install
npm run tauri dev
4. Pomotroid opens, but only an unstyled 25:00 is visible in the center of the window.

Expected behavior

The complete Pomotroid UI should be rendered, including the timer dial, theme/styles, controls, and navigation.

Things I have already tried

I verified that this is not caused by the window being too small:
I have resized the window to approximately 500x500

I also tested the WebKitGTK graphics workarounds:
GDK_BACKEND=wayland \ WEBKIT_DISABLE_COMPOSITING_MODE=1 \ npm run tauri dev

Additional information

npm install completes successfully.
I can also provide:

• a screenshot
• npm run tauri dev output
• WebKitGTK debug output
• my Nix development shell configuration
  if useful.