Add launch crash detection with detailed error dialog, fix all warnings

src/core/updater.rs

@@ -390,6 +390,7 @@ fn extract_update_info_runtime(path: &Path) -> Option<String> {
 // -- GitHub/GitLab API types for JSON deserialization --
 
 #[derive(Deserialize)]
+#[allow(dead_code)]
 struct GhRelease {
     tag_name: String,
     name: Option<String>,
@@ -405,6 +406,7 @@ struct GhAsset {
 }
 
 #[derive(Deserialize)]
+#[allow(dead_code)]
 struct GlRelease {
     tag_name: String,
     name: Option<String>,