refactor(multi-account): in-app overlay dialog for Add Account

Replaced DialogWindow (OS native window with title bar, minimize/maximize)
with Dialog composable (in-app overlay with scrim). Matches the
ComposeNoteDialog pattern used elsewhere in the desktop app.

- Card wrapper with 480dp width, 24dp padding
- Title row with 'Add Account' + Close (✕) icon
- No OS window chrome — clean in-app feel
- Click outside or ✕ to dismiss

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/account/AddAccountDialog.kt

@@ -20,36 +20,31 @@
  */
 package com.vitorpamplona.amethyst.desktop.ui.account
 
-import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.Close
-import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Card
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Text
-import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.unit.DpSize
 import androidx.compose.ui.unit.dp
-import androidx.compose.ui.window.DialogWindow
+import androidx.compose.ui.window.Dialog
-import androidx.compose.ui.window.rememberDialogState
 import com.vitorpamplona.amethyst.desktop.account.AccountManager
 import com.vitorpamplona.amethyst.desktop.ui.auth.LoginCard
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 
-@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun AddAccountDialog(
     accountManager: AccountManager,
@@ -59,36 +54,28 @@ fun AddAccountDialog(
     val scope = rememberCoroutineScope()
     val loginProgress by accountManager.loginProgress.collectAsState()
 
-    DialogWindow(
+    Dialog(onDismissRequest = onDismiss) {
-        onCloseRequest = onDismiss,
+        Card(modifier = Modifier.width(480.dp).padding(16.dp)) {
-        title = "Add Account",
+            Column(modifier = Modifier.padding(24.dp)) {
-        state = rememberDialogState(size = DpSize(480.dp, 600.dp)),
+                // Header with title + close button
-        resizable = false,
+                Row(verticalAlignment = Alignment.CenterVertically) {
-    ) {
+                    Text(
-        MaterialTheme {
+                        "Add Account",
-            Scaffold(
+                        style = MaterialTheme.typography.headlineSmall,
-                topBar = {
+                        color = MaterialTheme.colorScheme.onSurface,
-                    TopAppBar(
+                        modifier = Modifier.weight(1f),
-                        title = { Text("Add Account") },
+                    )
-                        navigationIcon = {
                     IconButton(onClick = onDismiss) {
                         Icon(
-                                    Icons.AutoMirrored.Filled.ArrowBack,
+                            Icons.Default.Close,
-                                    contentDescription = "Back",
+                            contentDescription = "Close",
+                            tint = MaterialTheme.colorScheme.onSurfaceVariant,
                         )
                     }
-                        },
+                }
-                    )
+
-                },
-            ) { padding ->
-                Column(
-                    modifier = Modifier.fillMaxSize().padding(padding).padding(24.dp),
-                    horizontalAlignment = Alignment.CenterHorizontally,
-                    verticalArrangement = Arrangement.Center,
-                ) {
                 LoginCard(
                     onLogin = { keyInput ->
-                            // All steps must be sequential — no fire-and-forget
                         scope.launch {
                             withContext(Dispatchers.IO) {
                                 accountManager.ensureCurrentAccountInStorage()
@@ -101,7 +88,6 @@ fun AddAccountDialog(
                                 onAccountAdded()
                             }
                         }
-                            // Return success to dismiss any error in LoginCard
                         Result.success(Unit)
                     },
                     onGenerateNew = {
@@ -117,7 +103,6 @@ fun AddAccountDialog(
                         }
                     },
                     onLoginBunker = { bunkerUri ->
-                            // ensureCurrentAccountInStorage first, then bunker login
                         accountManager.ensureCurrentAccountInStorage()
                         val result = accountManager.loginWithBunker(bunkerUri)
                         if (result.isSuccess) {
@@ -142,4 +127,3 @@ fun AddAccountDialog(
         }
     }
 }
-}