refactor: update dependencies and remove unused code

- Added new dependencies: `adler2`, `crc32fast`, `flate2`, `miniz_oxide`, and `libredox`.
- Updated existing dependencies: `tokio-rustls` to version 0.26.4 and `filetime` to version 0.2.27.
- Removed the `backup.rs` file as it is no longer needed.
- Introduced tests for configuration and credential management.
- Enhanced the `identity` module to generate W3C compliant DID documents.

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

neode-ui/src/types/api.ts

@@ -4,9 +4,19 @@ export interface DataModel {
   'server-info': ServerInfo
   'package-data': { [id: string]: PackageDataEntry }
   'peer-health'?: { [onion: string]: boolean }
+  notifications?: AppNotification[]
   ui: UIData
 }
 
+export interface AppNotification {
+  id: string
+  level: 'info' | 'warning' | 'error'
+  title: string
+  message: string
+  timestamp: string
+  app_id?: string
+}
+
 export interface ServerInfo {
   id: string
   version: string