fix(cli): enable keyring cli feature to restore use_native_store on keyring 4.1

[BryanFRD]

Closes #163.

CI (Rust CLI) has been red on main since the keyring 4.1.0/4.1.1 bumps (#159/#160): cargo clippy fails with error[E0425]: cannot find function use_native_store in crate keyring at cli/src/storage.rs:14.

Cause: keyring 4.1 split into default = ["v1"] and a cli feature, moving use_native_store into the cli module. We depend on keyring = "4" (default features) so it is no longer at the crate root.

Fix: keyring = { version = "4", default-features = false, features = ["cli"] }. The cli use_native_store(prefer_secret_service: bool) is behavior-identical to before (true = Secret Service on Linux), so cli/src/storage.rs is unchanged.

Verified locally: cargo check, cargo clippy --all-targets -- -D warnings, and cargo fmt --check all pass (Windows target). CI covers Linux.

Note / follow-up: the cli feature pulls a lot of transitive deps the CLI does not need (clap, rpassword, and db-keystore → a SQLite engine). The keyring maintainers explicitly recommend that real apps link keyring-core + only the platform store crates they need instead. A lean follow-up can drop keyring entirely and call keyring_core::set_default_store(<platform>::Store::new()) under #[cfg(target_os)] — happy to do that as a separate PR.

[BryanFRD]

Superseded by the lean keyring-core + platform-store version (no SQLite/clap bloat). See follow-up PR.