feat: Delete key removes items in source and profile lists

[Fikri-20]

Closes #2447

Added a Delete key shortcut to both the source files table and the profile selector list, wired to the existing remove/delete actions.

[Fikri-20]

hey @m3nu , could you please review the PR and tell me if I need to tweak anything else?

[Fikri-20]

Hi @m3nu, I'm applying for GSoC 2026 and have these PR ready for review. Could you please take a look?

[m3nu]

Review of PR #2469

Clean, focused PR. Reuses existing profile_delete_action and source_remove methods, so all validation (confirmation dialog, last-profile guard) is preserved. Tests cover both shortcuts. No new imports needed in production code.

Issues

1. macOS keyboard mismatch: Qt.Key.Key_Delete maps to the forward-delete key, which doesn't exist on most Mac keyboards (only full-size ones). On macOS, users expect Backspace (Qt's Key_Backspace) for deletion. The shortcut will be effectively unusable on most Macs. Consider adding Key_Backspace as an additional shortcut, or using QKeySequence.StandardKey.Delete which Qt maps platform-appropriately.

2. Inconsistent style between files:

   • main_window.py creates the shortcut inline: QShortcut(...).activated.connect(...)
   • source_tab.py uses a two-line pattern with a local variable, matching the existing shortcut_copy pattern in that file.

   The one-liner works (Qt parent-child ownership keeps it alive), but the two-line pattern is clearer and consistent with the rest of source_tab.

3. Exclusion tab not covered: The exclusion list also has a remove action. Not blocking, but worth considering for consistency.

[Fikri-20]

Hi @m3nu, thanks for the review! I've updated the PR to use QKeySequence.StandardKey.Delete for cross-platform compatibility as suggested. This should now work correctly on macOS laptops as well.

Let me know if any other tweaks are needed.