Dexie Observable Addon

Dexie.Observable is an addon for Dexie.js that significantly enhances IndexedDB functionality by enabling cross-window and cross-instance database change observation. It introduces an event mechanism, similar to `localStorage`'s `onstorage`, specifically for IndexedDB, allowing web applications to react in real-time to data modifications, irrespective of the originating tab or worker. This ensures views remain synchronized and up-to-date across all connected clients. The package is an integral part of the Dexie.js ecosystem, fully compatible with Dexie v4.x, and typically releases in alignment with Dexie.js's maintenance and feature updates. Although the package version provided is `4.0.1-beta.13`, it functions within the broader stable Dexie v4 environment. Furthermore, it forms the foundational layer for `Dexie.Syncable.js`, which provides robust two-way data replication capabilities with remote servers.