Fix capacitorAmberSigner: correct named export and setPackageName API

- Use named export { NostrSignerPlugin } not mod.default
- setPackageName takes a plain string not { packageName: string }
- isExternalSignerInstalled takes packageName as argument
- These were the exact bugs causing "plugin not available" error

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/lib/capacitorAmberSigner.ts

@@ -2,35 +2,40 @@
  * CapacitorAmberSigner
  *
  * A NostrSigner implementation that delegates all cryptographic operations
- * to the nostr-signer-capacitor-plugin, which in turn communicates with
- * Amber (or any NIP-55 compatible signer app) via native Android intents.
+ * to the nostr-signer-capacitor-plugin, which communicates with Amber
+ * (or any NIP-55 compatible signer app) via native Android intents.
  *
- * This ONLY works inside a Capacitor native app. On web/PWA use AmberSigner
- * (the intent:// URL redirect approach) instead.
- *
- * Usage:
- *   const signer = new CapacitorAmberSigner(pubkeyHex);
- *   const event = await signer.signEvent({ kind: 1, content: 'hello', tags: [], created_at: ... });
+ * This ONLY works inside a Capacitor native app on Android.
+ * On web/PWA the AmberSigner (URL redirect) is used instead.
  */
 
 import type { NostrEvent, NostrSigner } from '@nostrify/nostrify';
 import { nip19 } from 'nostr-tools';
 
-// Amber's package name on Android — used to target the correct signer app.
+// Amber's package name on Android
 const AMBER_PACKAGE_NAME = 'com.greenart7c3.nostrsigner';
 
 /**
- * Lazy-load the plugin and set the package name once.
- * Returns null if not running inside Capacitor (web/PWA fallback).
+ * Load the plugin using its correct named export: NostrSignerPlugin.
+ * The plugin calls ensureAndroid() internally — if not on Android it throws
+ * with code ANDROID_ONLY. We catch that and return null so the web/PWA
+ * path is used instead.
  */
 async function getPlugin() {
   try {
-    const mod = await import('nostr-signer-capacitor-plugin');
-    const plugin = mod.default ?? mod.NostrSignerPlugin;
-    if (!plugin) return null;
-    await plugin.setPackageName({ packageName: AMBER_PACKAGE_NAME });
-    return plugin;
-  } catch {
+    // Named export — NOT a default export
+    const { NostrSignerPlugin } = await import('nostr-signer-capacitor-plugin');
+    if (!NostrSignerPlugin) return null;
+    // setPackageName takes a plain string, not { packageName: string }
+    await NostrSignerPlugin.setPackageName(AMBER_PACKAGE_NAME);
+    return NostrSignerPlugin;
+  } catch (e: unknown) {
+    // ANDROID_ONLY error = not on Android (web/PWA) — silent fallback
+    // Any other error = plugin not loaded correctly — log it
+    const code = (e as { code?: string })?.code;
+    if (code !== 'ANDROID_ONLY') {
+      console.error('[CapacitorAmberSigner] getPlugin failed:', e);
+    }
     return null;
   }
 }
@@ -49,11 +54,9 @@ export class CapacitorAmberSigner implements NostrSigner {
   async signEvent(event: Omit<NostrEvent, 'id' | 'sig'>): Promise<NostrEvent> {
     const plugin = await getPlugin();
     if (!plugin) throw new Error('Capacitor Amber plugin not available');
-
     const { event: signedJson } = await plugin.signEvent({
       eventJson: JSON.stringify(event),
     });
-
     return JSON.parse(signedJson) as NostrEvent;
   }
 
@@ -88,24 +91,9 @@ export class CapacitorAmberSigner implements NostrSigner {
   };
 }
 
-/**
- * Check if the Amber signer app is installed on the device.
- * Returns false on web/PWA (plugin not available).
- */
-export async function isAmberInstalled(): Promise<boolean> {
-  const plugin = await getPlugin();
-  if (!plugin) return false;
-  try {
-    const { installed } = await plugin.isExternalSignerInstalled();
-    return installed;
-  } catch {
-    return false;
-  }
-}
-
 /**
  * Request the public key from Amber via the Capacitor plugin.
- * Returns the hex pubkey string, or throws on failure/cancel.
+ * Returns hex pubkey string. Throws on failure or cancellation.
  */
 export async function getAmberPublicKeyViaPlugin(): Promise<string> {
   const plugin = await getPlugin();
@@ -118,3 +106,17 @@ export async function getAmberPublicKeyViaPlugin(): Promise<string> {
   if (decoded.type !== 'npub') throw new Error('Unexpected key format from Amber plugin');
   return decoded.data as string;
 }
+
+/**
+ * Check if Amber is installed. Returns false on web/PWA.
+ */
+export async function isAmberInstalled(): Promise<boolean> {
+  const plugin = await getPlugin();
+  if (!plugin) return false;
+  try {
+    const { installed } = await plugin.isExternalSignerInstalled(AMBER_PACKAGE_NAME);
+    return installed;
+  } catch {
+    return false;
+  }
+}