fix: guard against malformed stored settings (crash → blank window); add ErrorBoundary to surface render errors

src/settings.ts

@@ -52,12 +52,18 @@ export function createApinexProvider (): ProviderConfig {
 }
 
 export async function loadSettings (): Promise<Settings> {
+  const defaults = defaultSettings()
   try {
     const stored = await figma.clientStorage.getAsync(SETTINGS_KEY)
-    if (stored == null || stored.version !== 1) return defaultSettings()
-    return stored as Settings
+    if (stored == null || stored.version !== 1) return defaults
+    const merged: Settings = { ...defaults, ...(stored as Settings) }
+    if (!Array.isArray(merged.providers) || merged.providers.length === 0) {
+      merged.providers = defaults.providers
+      merged.activeProviderId = defaults.providers[0].id
+    }
+    return merged
   } catch (e) {
-    return defaultSettings()
+    return defaults
   }
 }