Input rebinding settings with scrollable menu support

[vanlueckn]

Summary

• Reorganize settings menu to give input rebinding its own section instead of burying it under Gameplay
• Add mouse wheel scrolling to menu lists; keyboard selection auto-scrolls only when selection changes, not every frame
• Remove dead code from audio system that tracked one-shot voice replacement (STEAL tween and shots HashMap)
• Update i18n keys for both English and German

Testing

• Navigate settings menu with arrow keys and verify all rows are reachable without wrapping
• Scroll menu with mouse wheel and confirm list moves independently of selection cursor
• Press Enter on the Input section to open controls rebinding page
• Verify ← / → keys do not activate on the Input row (only Enter opens the page)
• Confirm settings values still update correctly with arrow keys on other rows
• Test wrapping behavior at menu boundaries (↑ from first value, ↓ from last value)
• Not run: audio system regression testing (change is simplification, not new feature)