Fix user manager forgets which key IDs are checked (#450)

[nogeenhenk]

Summary

• Fix Pass::getRecipientString() properly setting the count parameter
• The bug caused the UsersDialog to always treat selected keys as missing, adding "Key not found" entries instead

Related

• Fixes user manager forgets which key ids are checked #450

[coveralls]

coverage: 18.381% (+0.5%) from 17.849%
when pulling 4140ad3 on fix/450-user-manager-forgets-checked-keys
into d5764ae on main.

[nogeenhenk]

Testplan

Basic Test (Main Fix)

1. Open QtPass with an initialized password store
2. Select a folder in the tree view
3. Open Users dialog (Menu → Users or click toolbar button)
4. Check 1-2 GPG keys and click OK
5. Verify .gpg-id file contains the selected key IDs
6. Re-open Users dialog for the same folder
7. Expected: Previously selected keys should now be checked

Subfolder Test (Related)

1. Create a subfolder with its own .gpg-id file
2. Select different recipients for the subfolder
3. Re-open Users dialog for the subfolder
4. Expected: Subfolder's own recipients are shown

Edge Cases

• Empty .gpg-id file - should show no keys checked
• Keys missing from keyring - should show "Key not found" with option to show invalid keys

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 23.83%. Comparing base (bbe81ae) to head (2f602c4).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #775      +/-   ##
==========================================
+ Coverage   23.01%   23.83%   +0.81%     
==========================================
  Files          38       38              
  Lines        2976     2979       +3     
==========================================
+ Hits          685      710      +25     
+ Misses       2291     2269      -22     

Flag	Coverage Δ
qtpass	23.83% <100.00%> (+0.81%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.