Fix: fall back to desktop pairing URL for HTTP endpoints

hostedPairingUrl (via buildHostedPairingUrl) always returned a string
when endpointUrl was truthy, making the ?? fallback to
resolveDesktopPairingUrl unreachable dead code. This caused all
shareable pairing links to point to the hosted HTTPS app even for
HTTP LAN backends, where browsers block mixed content.

Add isHostedPairingCompatible check so resolveHostedPairingUrl returns
null for non-HTTPS endpoints, allowing the nullish coalescing to
correctly fall through to the direct desktop pairing URL.

Author: cursoragent

apps/web/src/components/settings/ConnectionsSettings.tsx

@@ -250,7 +250,18 @@ function resolveDesktopPairingUrl(endpointUrl: string, credential: string): stri
   return setPairingTokenOnUrl(url, credential).toString();
 }
 
-function resolveHostedPairingUrl(endpointUrl: string, credential: string): string {
+function isHostedPairingCompatible(endpointUrl: string): boolean {
+  try {
+    return new URL(endpointUrl).protocol === "https:";
+  } catch {
+    return false;
+  }
+}
+
+function resolveHostedPairingUrl(endpointUrl: string, credential: string): string | null {
+  if (!isHostedPairingCompatible(endpointUrl)) {
+    return null;
+  }
   return buildHostedPairingUrl({
     host: endpointUrl,
     token: credential,