Build 66: disable clearnet update-check; drop sidecar build steps

Security (audit H-2): the legacy update check is OFF by default. It hit
code.gri.mw (GRIM's gitea) directly over CLEARNET via the old HttpClient —
leaking "this user runs Goblin" metadata on every wallet-list view, which
defeats the nothing-clearnet mixnet model, and it pointed at the wrong
project's releases anyway. Opt-in only until reworked to run over the
mixnet against Goblin's own releases.

Build: with the Nym SDK linked in-process there's no sidecar binary to
embed or bundle. linux/build_release.sh drops the GOBLIN_NYM_UNIX_BIN
embed (AppImage is one self-contained binary); scripts/android.sh stops
bundling nym-socks5-client into jniLibs (the cdylib links nym-sdk
directly); scripts/nym-android.sh deleted.

src/settings/config.rs

@@ -198,7 +198,12 @@ impl Default for AppConfig {
 			use_socks_proxy: None,
 			http_proxy_url: None,
 			socks_proxy_url: None,
-			check_updates: Some(true),
+			// Off by default: the legacy update check hits code.gri.mw (GRIM's
+			// gitea) directly over CLEARNET via the old HttpClient — it leaks
+			// "this user runs Goblin" metadata (defeating the nothing-clearnet
+			// mixnet model) and points at the wrong project's releases. Opt-in
+			// only until reworked to run over the mixnet against Goblin releases.
+			check_updates: Some(false),
 			app_update: None,
 		}
 	}
@@ -537,7 +542,7 @@ impl AppConfig {
 	/// Check updates on startup.
 	pub fn check_updates() -> bool {
 		let r_config = Settings::app_config_to_read();
-		r_config.check_updates.unwrap_or(true)
+		r_config.check_updates.unwrap_or(false)
 	}
 
 	/// Disable or enable updates checking.