Read state lost: Articles revert to unread (Local RSS)

Checklist

• I've already searched in existing issues and haven't found a similar problem reported.
• I'm using the latest version of the app
• This error caused the app to crash
• This error is reproducible

Which category best fits this error?

Feed Sync

App version

0.16.1

Reproduction steps

Account Type: Local RSS (No external sync services)
Sorting Method: Earlier First

What is happening:
When there is a buildup of unread articles over time, reading some articles and backing out to the main feeds list does not mark them as read. Because they remain unread, I am forced to use the "mark all as read" option just to clear the list. However, even after forcing them as read, when the app refreshes naturally later on (e.g., after a few hours when new articles are published), roughly 50+ previously read items (even from 1-2 days ago) reappear as unread. This happens simultaneously across all feeds (France24, DW, Lowy Institute, etc.). I tried clearing the app data to reset everything, but the issue persists.

Expected behavior:
Simply opening and reading articles should automatically and permanently mark them as read when backing out. I should not have to rely on the "mark all as read" button as a workaround. Furthermore, once articles are read, they should never resurface into the unread list after natural feed refreshes later in the day.

Steps to reproduce:

1. Add standard RSS feeds (e.g., https://www.france24.com/en/rss) using a Local account.
2. Set sorting to "Earlier First".
3. Allow a backlog of unread articles to accumulate over some time.
4. Open and read a few articles in the "Unread" section, then back out to the main feeds list (notice they remain unread).
5. Use the "Mark all feeds as read" option to forcefully clear the accumulated unread items.
6. Let the app refresh over the course of regular usage (e.g., check back after a few hours when new articles hit the RSS feeds).
7. Observe that dozens of previously read articles from past days reappear in the Unread list.

Crash report

Start by reproducing the issue with a Local RSS account, Earlier First sorting, and the listed feed-refresh sequence. Trace how opening articles and using “Mark all feeds as read” affects read state before and after a natural refresh. Done means read articles stay read and do not reappear in the Unread list.