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>

core/archipelago/src/api/rpc/mod.rs

@@ -6,6 +6,7 @@ mod content;
 mod credentials;
 mod dwn;
 mod federation;
+mod handshake;
 mod identity;
 mod interfaces;
 mod marketplace;
@@ -297,6 +298,11 @@ impl RpcHandler {
             "node.nostr-pubkey" => self.handle_node_nostr_pubkey().await,
             "node-nostr-verify-revoked" => self.handle_node_nostr_verify_revoked().await,
 
+            // Encrypted peer handshake (NIP-44)
+            "handshake.discover" => self.handle_handshake_discover().await,
+            "handshake.connect" => self.handle_handshake_connect(params).await,
+            "handshake.poll" => self.handle_handshake_poll().await,
+
             // TOTP 2FA
             "auth.totp.setup.begin" => self.handle_totp_setup_begin(params).await,
             "auth.totp.setup.confirm" => self.handle_totp_setup_confirm(params).await,