[Nice-to-Have] Move to Trash Instead of Permanent Delete

[7sg56]

Priority: Nice-to-Have (Can Ship Without)

Currently delete_note uses fs::remove_file which is permanent. Using the OS trash (trash crate on the Rust side) would be safer and match what "Move to Trash" in the context menu implies.

Scope

• Replace fs::remove_file / fs::remove_dir_all with the trash crate's delete function.
• Ensure cross-platform support (macOS, Windows, Linux).

Source: changelogs/cinder-v0.2.md