feat(ui): credit The DragonX Developers in the About tab

Add "The DragonX Developers" to the About-tab credits (after The Hush
Developers), acknowledging the DragonX chain/daemon this wallet drives.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ui/pages/settings_page.cpp

@@ -2543,6 +2543,7 @@ void RenderSettingsPage(App* app) {
             ImGui::PushFont(body2);
             static const char* kCredits[] = {
                 "The Hush Developers",
+                "The DragonX Developers",
                 "ObsidianDragon Community",
                 "Dear ImGui \xE2\x80\x94 Omar Cornut",
                 "SDL3 \xE2\x80\x94 Sam Lantinga",