feat(input): add toggle in settings for readline-style shortcuts

[mcnomer]

Summary

Added toggle in Launcher settings panel to enable/disable readline-style shortcuts in the launcher. They are enabled by default, so no change from before.

Motivation

None of the other input fields in the UI have Readline shortcuts enabled, so I wanted to add a setting so that people who want consistency across the fields can disable them. However, as they were enabled by default before, I set the default to enabled.

Type of Change

• Bug fix
• New feature
• Breaking change
• Refactoring
• Build / packaging

Related Issue

#3946 is the PR where these were added.

Testing

• manually checked functionality when toggle is on and off.
• just format, just test, just lint, python3 tools/i18n-check.py

Manual Coverage

• Tested on Niri
• Tested on Hyprland
• Tested on Sway
• Tested on another compositor:
• Tested with different bar positions and density settings
• Tested at different interface scaling values
• Tested with multiple monitors

Screenshots / Videos

untitled.mp4

Checklist

• This PR is ready for review, or it is marked as Draft.
• I read and followed the relevant guidance in CONTRIBUTING.md.
• I ran just format with clang-format v22+ installed, or this PR has no code changes.
• I ran the relevant build or test commands, or explained why they were not run.
• I self-reviewed the changes.
• I checked for new warnings or errors.
• I will update end-user documentation after merge, or this PR does not change user-facing configuration or behavior.
• I added or updated assets/translations/en.json, or this PR adds no new user-facing strings.
• I did not edit non-English translation files unless this PR is explicitly for translation tooling, an import/export sync, or a maintainer-requested locale change.
• I used the existing canonical names for config keys, IPC names, paths, and identifiers.

Additional Notes