fix incorrect view reset when unmounting similarly-named devices

fix incorrect view reset when unmounting similarly-named devices

Problem
When unmounting a device, Dolphin could incorrectly reset views showing similarly-named paths due to substring matching.

Example of the issue

1. With two mounted devices:
   • /media/vk/test_disk
   • /media/vk/test_disk_2
2. Unmounting /media/vk/test_disk would incorrectly reset both views

Solution
Now properly detects views showing either:

• The exact mounted path
• Its subdirectories

Testing procedure

1. Mount two devices:
   • /media/vk/test_disk
   • /media/vk/test_disk_2
2. Open both in separate views
3. Unmount /media/vk/test_disk

Results

Check	Before	After
Behavior	Both views reset	Only correct view resets
Video	unmount_before	unmount_after