feat: improve mobile native impl (#14481)

fix #13529 

#### PR Dependency Tree


* **PR #14481** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Mobile blob caching with file-backed storage for faster loads and
reduced network usage
* Blob decoding with lazy refresh on token-read failures for improved
reliability
  * Full-text search/indexing exposed to mobile apps
* Document sync APIs and peer clock management for robust cross-device
sync

* **Tests**
* Added unit tests covering payload decoding, cache safety, and
concurrency

* **Dependencies**
* Added an LRU cache dependency and a new mobile-shared package for
shared mobile logic
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/native/nbstore/src/error.rs

@@ -8,6 +8,8 @@ pub enum Error {
   SqlxError(#[from] sqlx::Error),
   #[error("Migrate Error: {0}")]
   MigrateError(#[from] sqlx::migrate::MigrateError),
+  #[error("Connection in progress")]
+  ConnectionInProgress,
   #[error("Invalid operation")]
   InvalidOperation,
   #[error("Serialization Error: {0}")]