feat(android): implement private Rust storage runtime (#90)

crates/mobile-bridge/src/lib.rs

@@ -3,6 +3,9 @@
 
 //! Shared UniFFI contract for native phone presentation. Watch exports are opt-in.
 
+mod private_storage;
+pub use private_storage::*;
+
 use std::{
     error::Error,
     fmt,