improve error handling for qr scanner

composeApp/src/androidMain/kotlin/su/reya/coop/screens/ImportScreen.kt

@@ -94,17 +94,18 @@ fun ImportScreen() {
     LaunchedEffect(qrScanResult.content) {
         qrScanResult.content?.let { result ->
             runCatching {
-                if (result.startsWith("nsec")) {
+                if (result.startsWith("nsec1")) {
                     Keys.parse(result)
                 } else if (result.startsWith("bunker://")) {
                     NostrConnectUri.parse(result)
                 } else {
-                    throw IllegalArgumentException("Invalid secret: $result")
+                    throw IllegalArgumentException("Unsupported secret format")
                 }
+            }.onSuccess {
+                secret = result
+            }.onFailure { e ->
+                snackbarHostState.showSnackbar("Invalid secret: ${e.message}")
             }
-                .onSuccess { it -> secret = result }
-                .onFailure { e -> println("Failed to parse QR: ${e.message}") }
-
             // Clear the nav state
             qrScanResult.clear()
         }

composeApp/src/androidMain/kotlin/su/reya/coop/screens/NewChatScreen.kt

@@ -109,14 +109,13 @@ fun NewChatScreen() {
     LaunchedEffect(qrScanResult.content) {
         qrScanResult.content?.let { result ->
             // Verify the content
-            runCatching { PublicKey.parse(result) }
-                .onSuccess { pubkey ->
-                    selectedReceivers.add(pubkey)
-                }
-                .onFailure { e ->
-                    println("Failed to parse QR: ${e.message}")
-                }
-
+            runCatching {
+                PublicKey.parse(result)
+            }.onSuccess { pubkey ->
+                selectedReceivers.add(pubkey)
+            }.onFailure { e ->
+                snackbarHostState.showSnackbar("Invalid address: ${e.message}")
+            }
             // Clear the nav state
             qrScanResult.clear()
         }

composeApp/src/androidMain/kotlin/su/reya/coop/screens/ScanScreen.kt

@@ -98,12 +98,12 @@ fun ScanScreen() {
                     .border(2.dp, Color.White, RoundedCornerShape(12.dp))
             )
             Text(
+                modifier = Modifier
+                    .align(Alignment.BottomCenter)
+                    .padding(bottom = 64.dp),
                 text = "Scan a Nostr address",
                 style = MaterialTheme.typography.titleSmallEmphasized,
                 color = Color.White,
-                modifier = Modifier
-                    .align(Alignment.BottomCenter)
-                    .padding(bottom = 64.dp)
             )
         }
     }