Build 25: default to a steadier instant node + add the Goblin node

main.gri.mw has intermittent issues, so the default external ("instant") node
is now grincoin.org — both the onboarding first-connect and the head of the
external-node list. Adds the Goblin-run node https://main.us-ea.st as a default
option. (Relays already default to ours, nrelay.us-ea.st, plus relay.damus.io
and nos.lol — no change needed.)

src/gui/views/goblin/onboarding.rs

@@ -76,7 +76,7 @@ impl Default for OnboardingContent {
 		Self {
 			step: Step::Intro,
 			integrated: true,
-			ext_url: "https://main.gri.mw".to_string(),
+			ext_url: "https://grincoin.org".to_string(),
 			restore: false,
 			name: "Main wallet".to_string(),
 			pass: String::new(),

src/wallet/connections/external.rs

@@ -38,10 +38,12 @@ pub struct ExternalConnection {
 	pub available: Option<bool>,
 }
 
-/// Default external node URL for main network.
-const DEFAULT_MAIN_URLS: [&'static str; 3] = [
-	"https://main.gri.mw",
+/// Default external node URLs for main network. grincoin.org leads (main.gri.mw
+/// has intermittent issues); main.us-ea.st is the Goblin-run node.
+const DEFAULT_MAIN_URLS: [&'static str; 4] = [
 	"https://grincoin.org",
+	"https://main.us-ea.st",
+	"https://main.gri.mw",
 	"https://mainnet.grinffindor.org",
 ];