jj fragility in relation to AppleDouble files #9775

Description

I stumbled across a bug today whereby jj is fragile when it comes to dealing with AppleDouble files.

Steps to Reproduce the Problem

1. Do some jj stuff on a macOS box
2. tar -cvf coolProject.tar coolProject
3. On a Linux box (in my case Debian Trixie), tar -xvf coolProject.tar
4. Attempt to run jj st or any other jj command
5. Witness the chaos
6. rm -rf coolproject && tar -xvf repo.tar --exclude='._*'
7. Attempt to run jj st or any other jj command
8. jj operates normally

Yes, in theory this can be resolved user-side with correct tar or untar, but in practice I think jj could be a lot smarter and less fragile.

Expected Behavior

Behaves as normal

Actual Behavior

$jj st
.... lots of error output skipped here ....
Internal error: Unexpected error from backend
Caused by:
1: Failed to read non-git metadata
2: Failed to load table segment '._c63ab96cf65d09601fe0bbf1f00785070d2617c74633d4fcacecdff781a3f41cbcc39a7a3d926f0e3c36fd8da772feccd8b3b3a04442065b4a0c9acecd5e6a7b'
3: failed to fill whole buffer

Specifications

• Platform: macOS 26.5.2, debian trixie
• Version: jj 0.43.0 on both mac and linux