feat(wasm): default_vault_settings_json() for wizard parity with CLI init

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

crates/relicario-wasm/src/lib.rs

@@ -120,6 +120,16 @@ pub fn settings_encrypt(handle: &SessionHandle, settings_json: &str) -> Result<V
         .map_err(|e| JsError::new(&e.to_string()))
 }
 
+/// Returns the JSON for `VaultSettings::default()`. Used by the setup
+/// wizard to encrypt and write a default settings.enc on new-vault setup.
+/// Keeping this in WASM (instead of hand-encoding in TS) prevents drift
+/// when the default VaultSettings shape changes in Rust.
+#[wasm_bindgen]
+pub fn default_vault_settings_json() -> Result<String, JsError> {
+    let s = VaultSettings::default();
+    serde_json::to_string(&s).map_err(|e| JsError::new(&e.to_string()))
+}
+
 // ── Task 20: attachment / generator / imgsecret / ID / TOTP bridges ─────────
 
 use relicario_core::{decrypt_attachment, encrypt_attachment, FieldId, ItemId};