File list sometimes shows with white text instead of black

### ⚠️ This issue respects the following points: ⚠️

- [X] This is a **bug**. Not a [question or feature request](https://github.com/gsantner/markor/issues/new/choose).
- [X] The topic is **not** already reported at [Issues](https://github.com/gsantner/markor/issues?q=#js-issues-search). _(I've searched it)_.
- [X] Markor **is** up to date. See [Releases](https://github.com/gsantner/markor/tags) for the latest version. Updates are available from [F-Droid](https://f-droid.org/en/packages/net.gsantner.markor/) and GitHub.
- [X] The bug is still present in the latest development version (git master). (Please [download](https://nightly.link/gsantner/markor/workflows/build-android-project/master) and try the test version of Markor, named **Marder**. Don't worry; Markor and Marder appear as completely separate applications. You can install both side-by-side, and Markor settings are not touched. In case the issue is resolved there, you don't need to create a bug report. The change will be part of the next Markor update.)

### Description

When navigating up through folders, sometimes the file list turns white on light-grey background. Unusual and very hard to read. Normally it's black/dark on light-grey. I'm using the "light with dark toolbar" theme.

### Steps to reproduce

0. Make sure the theme is "light with dark toolbar".
1. Navigate to a document a couple folders deep (eg. `foo/bar/doc.md`).
2. Work on the document some (edit/view/edit again etc).
3. Press BACK, then BACK again. Should be at the `foo/` level now.
4. The files/folders list should suddenly turn white-on-lightgrey.

### Information

Android version: 14
Device: Samsung A53
App Version: 2.11.1 (148)

### Source

F-Droid

### Format / File type

Not specific

### Additional info / Log

_No response_

Reproduce the issue using the "light with dark toolbar" theme by navigating to a document several folders deep, editing it, and pressing Back twice. Trace the Android file-list screen and theme handling to identify why the text becomes white; done means the list remains readable with dark text on the light-grey background in this flow.

Written by the indexing model from the issue text.