Video mode Automatic sometimes does not act as documented

OS and Version (please complete the following information):

• Operating System: Debian Trixie
• Shotcut Version: shotcut-linux-x86_64-26.8.1.txz from the project download page

Describe the bug
Video mode Automatic sometimes does not act as documented: In contrast to what it says, it sometimes sets a frame rate that is different from the first video added.

Steps To Reproduce

1. Start Shotcut
2. Open a New Project, say Project name automatic_framerate
3. Select Video mode Automatic, which says "the resolution and frame rate are based on the first file you add to your project".
4. Quit Shotcut.
5. Restart Shotcut.
6. Open the previously created project, automatic_framerate.
7. The title says: automatic_framerate.mlt ... 25.00fps.
8. Add, as the first video, any video with 60fps.
9. The project unexpectedly remains at 25.00fps.

Expected behavior
The expected behaviour is that Shotcut does what it said: The frame rate is determined from the first video added, which is 60fps. Analogously for the resolution.

Can you reproduce this? Thank you a lot for Shotcut!

Reproduce the issue through New Project, Video mode Automatic, reopening the saved project, and adding a first 60fps video. Trace the project initialization and first-video handling entry points, then verify that reopening no longer locks the project to 25.00fps and that resolution still follows the first video.