Adopt Raycast common keyboard shortcuts (prefer-common-shortcut)

[altaywtf]

Part of the repo modernization program adjacent-findings backlog. Read the epic's operating rules before starting; re-read after context compaction.

Problem: 2 pre-existing @raycast/prefer-common-shortcut lint warnings in src/components/FileListItemActions.tsx:32,68 — custom shortcuts where Raycast defines platform-common ones.

Fix: adopt the common shortcuts (UX decision: confirm they don't collide with existing muscle memory), clearing the warnings.