Feature request: alphabetical sorting in / command palette and @ file picker

Feature request

Type: Nice-to-have / UX improvement

When typing / to invoke slash commands or @ to pick files, the items
appear in an undefined order. Alphabetical sorting (A→Z) as the default
would make scanning the list faster, especially as the number of custom
commands/skills grows.

With 8+ custom commands, finding the right one requires reading the entire
list. Alphabetical order lets you jump to the right area immediately —
the same reason file managers, IDEs, and shell completions default to
alphabetical sorting.