feat(privacylock): redesign Set/Change password dialog + snackbar

Rewrites SetPasswordDialog.kt with modern 2024-2026 UX. Adds
"Privacy lock enabled" / "Password updated" confirmation snackbars.

Dialog changes:
- Dialog + Surface(shape=shapes.large, tonal=6.dp) shell instead of
  default AlertDialog. Fixed width 440dp. Matches NewDmDialog.kt.
- Header row with Lock icon + title (titleLarge). Softer body copy
  under the header for the first-time-set path.
- Set-a-password flow uses ONE password field with a reveal toggle
  (Visibility / VisibilityOff, per-field independent). The reveal
  toggle IS the confirmation — no more "confirm password" field.
  Matches WhatsApp Chat Lock + macOS Users & Groups.
- Change-password flow uses two fields (current + new), each with
  its own reveal toggle. Current is verification, not redundancy.
- Real-time checklist row under the New field: green CheckCircle +
  "Min 6 characters" when satisfied, outlined Circle + muted text
  otherwise. Copy-pattern from EditProfileScreen NIP-05 status.
- Save button disabled until the checklist passes.
- Bumps PRIVACY_LOCK_MIN_PASSWORD_LENGTH from 4 to 6.
- Auto-focus first field on open (LaunchedEffect + FocusRequester).
- Enter submits (via onPreviewKeyEvent + KeyboardActions.onDone).
- Escape / click-outside-dismiss are disabled to prevent accidental
  loss of typed password (dismissOnClickOutside = false).
- Wrong-current error shown inline under the Current field.
- All reveal toggles reuse the KeyInputField.kt idiom verbatim.

Snackbar plumbing (scope-local — no CompositionLocal):
- PrivacyLockSettingsScreen owns a SnackbarHostState overlaid at
  Alignment.BottomCenter. LockToggleCard receives an onSaved
  callback, fires "Privacy lock enabled" on first-time set or
  "Password updated" on change.
- DesktopMessagesScreen (banner path) owns its own SnackbarHostState
  overlaid at BottomCenter. MessagesFirstRunBanner takes an
  optional onSaved callback (default {}), fires "Privacy lock
  enabled" after the dialog saves.

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/security/MessagesFirstRunBanner.kt

@@ -62,7 +62,7 @@ import com.vitorpamplona.amethyst.commons.privacylock.LocalMessagesLockState
  * content, so this composable never composes in that case).
  */
 @Composable
-fun MessagesFirstRunBanner() {
+fun MessagesFirstRunBanner(onSaved: (String) -> Unit = {}) {
     val settings = LocalPrivacyLockSettings.current
     val lockState = LocalMessagesLockState.current
     val enabled by settings.lockEnabled.collectAsState()
@@ -123,6 +123,7 @@ fun MessagesFirstRunBanner() {
                 // right after they just entered the password.
                 lockState.onUnlockSuccess()
                 showDialog = false
+                onSaved("Privacy lock enabled")
             },
         )
     }

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/security/SetPasswordDialog.kt

@@ -22,29 +22,65 @@ package com.vitorpamplona.amethyst.desktop.security
 
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
-import androidx.compose.material3.AlertDialog
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.Button
+import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.input.key.Key
+import androidx.compose.ui.input.key.KeyEventType
+import androidx.compose.ui.input.key.key
+import androidx.compose.ui.input.key.onPreviewKeyEvent
+import androidx.compose.ui.input.key.type
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.input.PasswordVisualTransformation
+import androidx.compose.ui.text.input.VisualTransformation
 import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.Dialog
+import androidx.compose.ui.window.DialogProperties
+import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
+import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
+
+/** Enforced minimum length for a new/rotated password. */
+const val PRIVACY_LOCK_MIN_PASSWORD_LENGTH = 6
 
 /**
  * Set or change the privacy-lock password.
  *
  * Pass [existingHash] = null when the user hasn't set a password yet
  * (first-run banner path, or a fresh Settings toggle). In that case the
- * "current password" field is hidden. Pass a real hash to force
+ * dialog shows a single New password field with a reveal toggle. Pass a
- * verification of the current password before letting the user rotate.
+ * real hash to force verification of the current password before letting
+ * the user rotate — the dialog then shows a Current password field
+ * followed by the New password field, each with its own reveal toggle.
  *
  * On successful validation, [onConfirm] is invoked with a fresh
  * `salt$hash` string ready for [com.vitorpamplona.amethyst.commons.privacylock.PrivacyLockSettings.setPasswordHashed].
+ *
+ * UX: auto-focus the first field on open, Enter submits, Escape cancels.
+ * Real-time checklist under the New password field shows a green ✓ once
+ * the length threshold is reached. Reveal toggles are per-field
+ * independent so revealing Current does not reveal New.
  */
 @Composable
 fun SetPasswordDialog(
@@ -52,74 +88,207 @@ fun SetPasswordDialog(
     onDismiss: () -> Unit,
     onConfirm: (String) -> Unit,
 ) {
+    val isChange = existingHash != null
     var current by remember { mutableStateOf("") }
-    var new1 by remember { mutableStateOf("") }
+    var new by remember { mutableStateOf("") }
-    var new2 by remember { mutableStateOf("") }
+    var currentError by remember { mutableStateOf<String?>(null) }
-    var error by remember { mutableStateOf<String?>(null) }
+    var newError by remember { mutableStateOf<String?>(null) }
+
+    val firstFieldFocus = remember { FocusRequester() }
 
     val submit: () -> Unit = {
         val currentOk =
-            existingHash == null ||
+            !isChange ||
-                PasswordHasher.verify(current.toCharArray(), existingHash)
+                PasswordHasher.verify(current.toCharArray(), existingHash!!)
         when {
-            !currentOk -> error = "Current password is wrong"
+            !currentOk -> {
-            new1.length < 4 -> error = "New password must be at least 4 characters"
+                currentError = "Wrong password"
-            new1 != new2 -> error = "Passwords don't match"
+                newError = null
-            else -> onConfirm(PasswordHasher.hash(new1.toCharArray()))
+            }
+            new.length < PRIVACY_LOCK_MIN_PASSWORD_LENGTH -> {
+                currentError = null
+                newError = "Must be at least $PRIVACY_LOCK_MIN_PASSWORD_LENGTH characters"
+            }
+            else -> {
+                onConfirm(PasswordHasher.hash(new.toCharArray()))
+            }
         }
     }
 
-    AlertDialog(
+    LaunchedEffect(Unit) {
+        firstFieldFocus.requestFocus()
+    }
+
+    Dialog(
         onDismissRequest = onDismiss,
-        title = { Text(if (existingHash == null) "Set a password" else "Change password") },
+        properties = DialogProperties(dismissOnBackPress = true, dismissOnClickOutside = false),
-        text = {
+    ) {
-            Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
+        Surface(
-                if (existingHash != null) {
+            shape = MaterialTheme.shapes.large,
-                    OutlinedTextField(
+            color = MaterialTheme.colorScheme.surface,
+            tonalElevation = 6.dp,
+            modifier = Modifier.width(440.dp),
+        ) {
+            Column(
+                modifier = Modifier.padding(24.dp).fillMaxWidth(),
+                verticalArrangement = Arrangement.spacedBy(16.dp),
+            ) {
+                DialogHeader(isChange = isChange)
+
+                if (!isChange) {
+                    Text(
+                        text = "Choose a password to lock the Messages tab. You'll enter it to unlock later.",
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+
+                if (isChange) {
+                    PasswordField(
                         value = current,
                         onValueChange = {
                             current = it
-                            error = null
+                            currentError = null
                         },
-                        label = { Text("Current password") },
+                        label = "Current password",
-                        singleLine = true,
+                        errorMessage = currentError,
-                        visualTransformation = PasswordVisualTransformation(),
+                        modifier = Modifier.focusRequester(firstFieldFocus),
+                        imeAction = ImeAction.Next,
+                        onImeAction = { /* Tab handled by focus system */ },
                     )
                 }
-                OutlinedTextField(
+
-                    value = new1,
+                PasswordField(
+                    value = new,
                     onValueChange = {
-                        new1 = it
+                        new = it
-                        error = null
+                        newError = null
                     },
-                    label = { Text("New password") },
+                    label = "New password",
-                    singleLine = true,
+                    errorMessage = newError,
-                    visualTransformation = PasswordVisualTransformation(),
+                    modifier =
+                        if (isChange) Modifier else Modifier.focusRequester(firstFieldFocus),
+                    imeAction = ImeAction.Done,
+                    onImeAction = { submit() },
                 )
-                OutlinedTextField(
+
-                    value = new2,
+                RequirementChecklistRow(satisfied = new.length >= PRIVACY_LOCK_MIN_PASSWORD_LENGTH)
-                    onValueChange = {
+
-                        new2 = it
+                Row(
-                        error = null
+                    modifier = Modifier.fillMaxWidth(),
-                    },
+                    horizontalArrangement = Arrangement.End,
-                    label = { Text("Confirm new password") },
+                ) {
-                    singleLine = true,
+                    TextButton(onClick = onDismiss) { Text("Cancel") }
-                    visualTransformation = PasswordVisualTransformation(),
+                    Button(
-                )
+                        onClick = submit,
-                error?.let {
+                        enabled = new.length >= PRIVACY_LOCK_MIN_PASSWORD_LENGTH,
-                    Text(
+                    ) {
-                        text = it,
+                        Text("Save")
-                        color = MaterialTheme.colorScheme.error,
+                    }
-                        style = MaterialTheme.typography.bodySmall,
-                    )
                 }
             }
+        }
+    }
+}
+
+@Composable
+private fun DialogHeader(isChange: Boolean) {
+    Row(
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(12.dp),
+    ) {
+        Icon(
+            symbol = MaterialSymbols.Lock,
+            contentDescription = null,
+            modifier = Modifier.size(24.dp),
+            tint = MaterialTheme.colorScheme.primary,
+        )
+        Text(
+            text = if (isChange) "Change password" else "Set a password",
+            style = MaterialTheme.typography.titleLarge,
+        )
+    }
+}
+
+@Composable
+private fun PasswordField(
+    value: String,
+    onValueChange: (String) -> Unit,
+    label: String,
+    errorMessage: String?,
+    modifier: Modifier = Modifier,
+    imeAction: ImeAction = ImeAction.Done,
+    onImeAction: () -> Unit = {},
+) {
+    var revealed by remember { mutableStateOf(false) }
+
+    OutlinedTextField(
+        value = value,
+        onValueChange = onValueChange,
+        label = { Text(label) },
+        modifier =
+            modifier
+                .fillMaxWidth()
+                .onPreviewKeyEvent { event ->
+                    if (event.type == KeyEventType.KeyDown && event.key == Key.Enter && imeAction == ImeAction.Done) {
+                        onImeAction()
+                        true
+                    } else {
+                        false
+                    }
+                },
+        singleLine = true,
+        visualTransformation = if (revealed) VisualTransformation.None else PasswordVisualTransformation(),
+        keyboardOptions =
+            KeyboardOptions(
+                keyboardType = KeyboardType.Password,
+                imeAction = imeAction,
+            ),
+        keyboardActions = KeyboardActions(onDone = { onImeAction() }, onNext = { onImeAction() }),
+        trailingIcon = {
+            IconButton(onClick = { revealed = !revealed }) {
+                Icon(
+                    symbol = if (revealed) MaterialSymbols.VisibilityOff else MaterialSymbols.Visibility,
+                    contentDescription = if (revealed) "Hide password" else "Show password",
+                )
+            }
         },
-        confirmButton = {
+        isError = errorMessage != null,
-            TextButton(onClick = submit) { Text("Save") }
+        supportingText =
-        },
+            errorMessage?.let {
-        dismissButton = {
+                {
-            TextButton(onClick = onDismiss) { Text("Cancel") }
+                    Text(it, color = MaterialTheme.colorScheme.error)
-        },
+                }
+            },
     )
 }
+
+@Composable
+private fun RequirementChecklistRow(satisfied: Boolean) {
+    Row(
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(8.dp),
+    ) {
+        Icon(
+            symbol = if (satisfied) MaterialSymbols.CheckCircle else MaterialSymbols.Circle,
+            contentDescription = null,
+            modifier = Modifier.size(16.dp),
+            tint =
+                if (satisfied) {
+                    MaterialTheme.colorScheme.primary
+                } else {
+                    MaterialTheme.colorScheme.onSurfaceVariant
+                },
+        )
+        Text(
+            text = "Min $PRIVACY_LOCK_MIN_PASSWORD_LENGTH characters",
+            style = MaterialTheme.typography.bodySmall,
+            color =
+                if (satisfied) {
+                    MaterialTheme.colorScheme.onSurface
+                } else {
+                    MaterialTheme.colorScheme.onSurfaceVariant
+                },
+        )
+    }
+}

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/chats/DesktopMessagesScreen.kt

@@ -29,9 +29,12 @@ import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
@@ -67,6 +70,7 @@ import com.vitorpamplona.amethyst.desktop.network.DesktopRelayConnectionManager
 import com.vitorpamplona.amethyst.desktop.security.MessagesFirstRunBanner
 import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
 import java.awt.Cursor
 
 private val isMacOS = System.getProperty("os.name").lowercase().contains("mac")
@@ -128,37 +132,48 @@ fun DesktopMessagesScreen(
             }
         }
 
-    Column(modifier = Modifier.fillMaxSize()) {
+    val snackbarHostState = remember { SnackbarHostState() }
-        MessagesFirstRunBanner()
+    val snackbarScope = rememberCoroutineScope()
-        Box(modifier = Modifier.weight(1f)) {
+
-            if (compactMode) {
+    Box(modifier = Modifier.fillMaxSize()) {
-                CompactMessagesContent(
+        Column(modifier = Modifier.fillMaxSize()) {
-                    selectedRoom = selectedRoom,
+            MessagesFirstRunBanner(onSaved = { msg ->
-                    listState = listState,
+                snackbarScope.launch { snackbarHostState.showSnackbar(msg) }
-                    account = account,
+            })
-                    cacheProvider = cacheProvider,
+            Box(modifier = Modifier.weight(1f)) {
-                    scope = scope,
+                if (compactMode) {
-                    onNavigateToProfile = onNavigateToProfile,
+                    CompactMessagesContent(
-                    listFocusRequester = listFocusRequester,
+                        selectedRoom = selectedRoom,
-                    onShowNewDm = { showNewDmDialog = true },
+                        listState = listState,
-                    onShowRelayPicker = { showDmRelayPicker = true },
+                        account = account,
-                    keyHandler = keyHandler,
+                        cacheProvider = cacheProvider,
-                )
+                        scope = scope,
-            } else {
+                        onNavigateToProfile = onNavigateToProfile,
-                SplitMessagesContent(
+                        listFocusRequester = listFocusRequester,
-                    selectedRoom = selectedRoom,
+                        onShowNewDm = { showNewDmDialog = true },
-                    listState = listState,
+                        onShowRelayPicker = { showDmRelayPicker = true },
-                    account = account,
+                        keyHandler = keyHandler,
-                    cacheProvider = cacheProvider,
+                    )
-                    scope = scope,
+                } else {
-                    onNavigateToProfile = onNavigateToProfile,
+                    SplitMessagesContent(
-                    listFocusRequester = listFocusRequester,
+                        selectedRoom = selectedRoom,
-                    onShowNewDm = { showNewDmDialog = true },
+                        listState = listState,
-                    onShowRelayPicker = { showDmRelayPicker = true },
+                        account = account,
-                    keyHandler = keyHandler,
+                        cacheProvider = cacheProvider,
-                )
+                        scope = scope,
+                        onNavigateToProfile = onNavigateToProfile,
+                        listFocusRequester = listFocusRequester,
+                        onShowNewDm = { showNewDmDialog = true },
+                        onShowRelayPicker = { showDmRelayPicker = true },
+                        keyHandler = keyHandler,
+                    )
+                }
             }
         }
+        SnackbarHost(
+            hostState = snackbarHostState,
+            modifier = Modifier.align(Alignment.BottomCenter).padding(16.dp),
+        )
     }
 
     if (showNewDmDialog) {

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/settings/PrivacyLockSettingsScreen.kt

@@ -21,6 +21,7 @@
 package com.vitorpamplona.amethyst.desktop.ui.settings
 
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
@@ -33,6 +34,8 @@ import androidx.compose.material3.DropdownMenu
 import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -40,6 +43,7 @@ import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -49,6 +53,7 @@ import com.vitorpamplona.amethyst.commons.privacylock.InactivityTimer
 import com.vitorpamplona.amethyst.commons.privacylock.PrivacyLockSettings
 import com.vitorpamplona.amethyst.desktop.security.LocalPrivacyLockSettings
 import com.vitorpamplona.amethyst.desktop.security.SetPasswordDialog
+import kotlinx.coroutines.launch
 
 /**
  * Desktop privacy-lock settings pane. Column + Card layout (no Scaffold) —
@@ -57,22 +62,39 @@ import com.vitorpamplona.amethyst.desktop.security.SetPasswordDialog
 @Composable
 fun PrivacyLockSettingsScreen() {
     val settings = LocalPrivacyLockSettings.current
-    Column(
+    val snackbarHostState = remember { SnackbarHostState() }
-        modifier =
+    val scope = rememberCoroutineScope()
-            Modifier
+
-                .fillMaxWidth()
+    Box(modifier = Modifier.fillMaxWidth()) {
-                .padding(16.dp),
+        Column(
-        verticalArrangement = Arrangement.spacedBy(16.dp),
+            modifier =
-    ) {
+                Modifier
-        LockToggleCard(settings)
+                    .fillMaxWidth()
-        InactivityCard(settings)
+                    .padding(16.dp),
-        RedactionCard(settings)
+            verticalArrangement = Arrangement.spacedBy(16.dp),
-        LimitationsCard()
+        ) {
+            LockToggleCard(
+                settings = settings,
+                onSaved = { message ->
+                    scope.launch { snackbarHostState.showSnackbar(message) }
+                },
+            )
+            InactivityCard(settings)
+            RedactionCard(settings)
+            LimitationsCard()
+        }
+        SnackbarHost(
+            hostState = snackbarHostState,
+            modifier = Modifier.align(Alignment.BottomCenter).padding(16.dp),
+        )
     }
 }
 
 @Composable
-private fun LockToggleCard(settings: PrivacyLockSettings) {
+private fun LockToggleCard(
+    settings: PrivacyLockSettings,
+    onSaved: (String) -> Unit,
+) {
     val enabled by settings.lockEnabled.collectAsState()
     val stored by settings.passwordHashed.collectAsState()
     var showSetPassword by remember { mutableStateOf(false) }
@@ -117,6 +139,7 @@ private fun LockToggleCard(settings: PrivacyLockSettings) {
     }
 
     if (showSetPassword) {
+        val wasFirstSet = stored == null
         SetPasswordDialog(
             existingHash = stored,
             onDismiss = {
@@ -128,6 +151,7 @@ private fun LockToggleCard(settings: PrivacyLockSettings) {
                 if (pendingEnable) settings.setLockEnabled(true)
                 showSetPassword = false
                 pendingEnable = false
+                onSaved(if (wasFirstSet) "Privacy lock enabled" else "Password updated")
             },
         )
     }