feat: add newsletter sending toggle in Composer publish dialog

- Add newsletter fields to ComposerUiState (enabled, newsletters list,
  selected newsletter, sendAsNewsletter, emailSegment, subscriber count,
  confirmation dialog state)
- Load newsletter data on init when newsletter features are enabled
- Add newsletter options in publish dropdown: send-as-newsletter switch,
  newsletter picker (radio buttons), email segment picker (All/Free/Paid)
- Show warning about irreversible email send with subscriber count
- Change publish button to tertiaryContainer color and email icon when
  newsletter sending is active
- Add NewsletterConfirmationDialog requiring "WYSLIJ" typed input to
  confirm, with summary of newsletter name, segment, count, and title
- Pass newsletter slug and email segment through to PostRepository
- Store newsletter slug in LocalPost for offline queue support

app/src/main/java/com/swoosh/microblog/ui/composer/ComposerScreen.kt

@@ -14,6 +14,8 @@ import androidx.compose.foundation.lazy.grid.GridCells
 import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
 import androidx.compose.foundation.lazy.grid.itemsIndexed
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.selection.selectable
+import androidx.compose.foundation.selection.selectableGroup
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
@@ -49,6 +51,7 @@ import com.swoosh.microblog.data.AccountManager
 import com.swoosh.microblog.data.HashtagParser
 import com.swoosh.microblog.data.SiteMetadataCache
 import com.swoosh.microblog.data.model.FeedPost
+import com.swoosh.microblog.data.model.GhostNewsletter
 import com.swoosh.microblog.data.model.GhostTagFull
 import com.swoosh.microblog.data.model.PostStats
 import com.swoosh.microblog.ui.animation.SwooshMotion
@@ -148,15 +151,23 @@ fun ComposerScreen(
                             )
                         }
                     } else {
+                        val isNewsletterPublish = state.sendAsNewsletter && state.selectedNewsletter != null
                         FilledIconButton(
                             onClick = viewModel::publish,
                             enabled = canSubmit,
                             colors = IconButtonDefaults.filledIconButtonColors(
-                                containerColor = MaterialTheme.colorScheme.primary,
+                                containerColor = if (isNewsletterPublish)
-                                contentColor = MaterialTheme.colorScheme.onPrimary
+                                    MaterialTheme.colorScheme.tertiaryContainer
+                                else MaterialTheme.colorScheme.primary,
+                                contentColor = if (isNewsletterPublish)
+                                    MaterialTheme.colorScheme.onTertiaryContainer
+                                else MaterialTheme.colorScheme.onPrimary
                             )
                         ) {
-                            Icon(Icons.Default.Send, "Publish")
+                            Icon(
+                                if (isNewsletterPublish) Icons.Default.Email else Icons.Default.Send,
+                                if (isNewsletterPublish) "Publish & Send Email" else "Publish"
+                            )
                         }
                     }
 
@@ -176,13 +187,24 @@ fun ComposerScreen(
                             expanded = showSendMenu,
                             onDismissRequest = { showSendMenu = false }
                         ) {
+                            val publishLabel = if (state.sendAsNewsletter && state.selectedNewsletter != null) {
+                                if (state.isEditing) "Update & Send Email" else "Publish & Send Email"
+                            } else {
+                                if (state.isEditing) "Update & Publish" else "Publish Now"
+                            }
                             DropdownMenuItem(
-                                text = { Text(if (state.isEditing) "Update & Publish" else "Publish Now") },
+                                text = { Text(publishLabel) },
                                 onClick = {
                                     showSendMenu = false
                                     viewModel.publish()
                                 },
-                                leadingIcon = { Icon(Icons.Default.Send, null) },
+                                leadingIcon = {
+                                    Icon(
+                                        if (state.sendAsNewsletter && state.selectedNewsletter != null)
+                                            Icons.Default.Email else Icons.Default.Send,
+                                        null
+                                    )
+                                },
                                 enabled = canSubmit
                             )
                             DropdownMenuItem(
@@ -203,6 +225,17 @@ fun ComposerScreen(
                                 leadingIcon = { Icon(Icons.Default.Schedule, null) },
                                 enabled = canSubmit
                             )
+
+                            // Newsletter options
+                            if (state.newsletterEnabled) {
+                                HorizontalDivider(modifier = Modifier.padding(vertical = 4.dp))
+                                NewsletterDropdownSection(
+                                    state = state,
+                                    onToggleSendAsNewsletter = viewModel::toggleSendAsNewsletter,
+                                    onSelectNewsletter = viewModel::selectNewsletter,
+                                    onSetEmailSegment = viewModel::setEmailSegment
+                                )
+                            }
                         }
                     }
                 }
@@ -690,6 +723,259 @@ fun ComposerScreen(
             }
         }
     }
+
+    // Newsletter confirmation dialog
+    val confirmNewsletter = state.selectedNewsletter
+    if (state.showNewsletterConfirmation && confirmNewsletter != null) {
+        NewsletterConfirmationDialog(
+            newsletterName = confirmNewsletter.name,
+            emailSegment = state.emailSegment,
+            subscriberCount = state.subscriberCount,
+            postTitle = state.text.take(60),
+            onConfirm = viewModel::confirmNewsletterSend,
+            onDismiss = viewModel::cancelNewsletterConfirmation
+        )
+    }
+}
+
+/**
+ * Newsletter options section in the publish dropdown menu.
+ */
+@Composable
+fun NewsletterDropdownSection(
+    state: ComposerUiState,
+    onToggleSendAsNewsletter: () -> Unit,
+    onSelectNewsletter: (GhostNewsletter) -> Unit,
+    onSetEmailSegment: (String) -> Unit
+) {
+    // Send as newsletter switch
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clickable(onClick = onToggleSendAsNewsletter)
+            .padding(horizontal = 12.dp, vertical = 8.dp),
+        horizontalArrangement = Arrangement.SpaceBetween,
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            text = "Send as newsletter",
+            style = MaterialTheme.typography.bodyMedium,
+            modifier = Modifier.weight(1f)
+        )
+        Switch(
+            checked = state.sendAsNewsletter,
+            onCheckedChange = { onToggleSendAsNewsletter() },
+            modifier = Modifier.padding(start = 8.dp)
+        )
+    }
+
+    // Newsletter picker and segment (only when sending)
+    AnimatedVisibility(
+        visible = state.sendAsNewsletter,
+        enter = fadeIn(SwooshMotion.quick()) + expandVertically(animationSpec = SwooshMotion.snappy()),
+        exit = fadeOut(SwooshMotion.quick()) + shrinkVertically(animationSpec = SwooshMotion.snappy())
+    ) {
+        Column(modifier = Modifier.padding(horizontal = 12.dp)) {
+            // Newsletter picker
+            if (state.availableNewsletters.size > 1) {
+                Text(
+                    text = "Newsletter:",
+                    style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.padding(top = 4.dp)
+                )
+                Column(modifier = Modifier.selectableGroup()) {
+                    state.availableNewsletters.forEach { newsletter ->
+                        Row(
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .selectable(
+                                    selected = state.selectedNewsletter?.id == newsletter.id,
+                                    onClick = { onSelectNewsletter(newsletter) }
+                                )
+                                .padding(vertical = 4.dp),
+                            verticalAlignment = Alignment.CenterVertically
+                        ) {
+                            RadioButton(
+                                selected = state.selectedNewsletter?.id == newsletter.id,
+                                onClick = { onSelectNewsletter(newsletter) }
+                            )
+                            Text(
+                                text = newsletter.name,
+                                style = MaterialTheme.typography.bodySmall,
+                                modifier = Modifier.padding(start = 4.dp)
+                            )
+                        }
+                    }
+                }
+            } else if (state.availableNewsletters.size == 1) {
+                Text(
+                    text = "Newsletter: ${state.availableNewsletters.first().name}",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.padding(vertical = 4.dp)
+                )
+            }
+
+            // Segment picker
+            Text(
+                text = "Send to:",
+                style = MaterialTheme.typography.labelSmall,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(top = 8.dp)
+            )
+            val segments = listOf("all" to "All subscribers", "status:free" to "Free members", "status:-free" to "Paid members")
+            Column(modifier = Modifier.selectableGroup()) {
+                segments.forEach { (value, label) ->
+                    Row(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .selectable(
+                                selected = state.emailSegment == value,
+                                onClick = { onSetEmailSegment(value) }
+                            )
+                            .padding(vertical = 2.dp),
+                        verticalAlignment = Alignment.CenterVertically
+                    ) {
+                        RadioButton(
+                            selected = state.emailSegment == value,
+                            onClick = { onSetEmailSegment(value) }
+                        )
+                        Text(
+                            text = label,
+                            style = MaterialTheme.typography.bodySmall,
+                            modifier = Modifier.padding(start = 4.dp)
+                        )
+                    }
+                }
+            }
+
+            // Warning text
+            val countText = state.subscriberCount?.let { "~$it" } ?: "your"
+            Text(
+                text = "\u26A0 Email will be sent to $countText subscribers. This cannot be undone.",
+                style = MaterialTheme.typography.labelSmall,
+                color = MaterialTheme.colorScheme.error,
+                modifier = Modifier.padding(vertical = 8.dp)
+            )
+        }
+    }
+}
+
+/**
+ * Confirmation dialog for newsletter sending.
+ * Requires typing "WYSLIJ" to confirm.
+ */
+@Composable
+fun NewsletterConfirmationDialog(
+    newsletterName: String,
+    emailSegment: String,
+    subscriberCount: Int?,
+    postTitle: String,
+    onConfirm: () -> Unit,
+    onDismiss: () -> Unit
+) {
+    var confirmInput by remember { mutableStateOf("") }
+    val isConfirmEnabled = confirmInput == "WYSLIJ"
+    val segmentLabel = when (emailSegment) {
+        "all" -> "All subscribers"
+        "status:free" -> "Free members"
+        "status:-free" -> "Paid members"
+        else -> emailSegment
+    }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = {
+            Text(
+                text = "Confirm Newsletter Send",
+                style = MaterialTheme.typography.titleMedium
+            )
+        },
+        text = {
+            Column {
+                Text(
+                    text = "You are about to send an email newsletter:",
+                    style = MaterialTheme.typography.bodyMedium
+                )
+                Spacer(modifier = Modifier.height(12.dp))
+
+                // Summary card
+                OutlinedCard(modifier = Modifier.fillMaxWidth()) {
+                    Column(modifier = Modifier.padding(12.dp)) {
+                        Text(
+                            text = "Newsletter: $newsletterName",
+                            style = MaterialTheme.typography.bodySmall,
+                            fontWeight = FontWeight.Bold
+                        )
+                        Text(
+                            text = "Segment: $segmentLabel",
+                            style = MaterialTheme.typography.bodySmall
+                        )
+                        if (subscriberCount != null) {
+                            Text(
+                                text = "Recipients: ~$subscriberCount",
+                                style = MaterialTheme.typography.bodySmall
+                            )
+                        }
+                        Text(
+                            text = "Post: ${postTitle.take(40)}${if (postTitle.length > 40) "..." else ""}",
+                            style = MaterialTheme.typography.bodySmall
+                        )
+                    }
+                }
+
+                Spacer(modifier = Modifier.height(12.dp))
+
+                // Warning
+                Text(
+                    text = "\u26A0 IRREVERSIBLE: Once sent, this email cannot be recalled.",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.error,
+                    fontWeight = FontWeight.Bold
+                )
+
+                Spacer(modifier = Modifier.height(12.dp))
+
+                // Confirmation input
+                Text(
+                    text = "Type WYSLIJ to confirm:",
+                    style = MaterialTheme.typography.labelMedium
+                )
+                Spacer(modifier = Modifier.height(4.dp))
+                OutlinedTextField(
+                    value = confirmInput,
+                    onValueChange = { confirmInput = it },
+                    modifier = Modifier.fillMaxWidth(),
+                    singleLine = true,
+                    placeholder = { Text("WYSLIJ") }
+                )
+            }
+        },
+        confirmButton = {
+            Button(
+                onClick = onConfirm,
+                enabled = isConfirmEnabled,
+                colors = ButtonDefaults.buttonColors(
+                    containerColor = MaterialTheme.colorScheme.error,
+                    contentColor = MaterialTheme.colorScheme.onError
+                )
+            ) {
+                Icon(
+                    Icons.Default.Email,
+                    contentDescription = null,
+                    modifier = Modifier.size(18.dp)
+                )
+                Spacer(modifier = Modifier.width(8.dp))
+                Text("Send Email")
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text("Cancel")
+            }
+        }
+    )
 }
 
 /**

app/src/main/java/com/swoosh/microblog/ui/composer/ComposerViewModel.kt

@@ -6,6 +6,7 @@ import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
 import com.swoosh.microblog.data.HashtagParser
 import com.swoosh.microblog.data.MobiledocBuilder
+import com.swoosh.microblog.data.NewsletterPreferences
 import com.swoosh.microblog.data.PreviewHtmlBuilder
 import com.swoosh.microblog.data.db.Converters
 import com.swoosh.microblog.data.model.*
@@ -27,6 +28,7 @@ class ComposerViewModel(application: Application) : AndroidViewModel(application
 
     private val repository = PostRepository(application)
     private val tagRepository = TagRepository(application)
+    private val newsletterPreferences = NewsletterPreferences(application)
     private val appContext = application
 
     private val _uiState = MutableStateFlow(ComposerUiState())
@@ -40,6 +42,7 @@ class ComposerViewModel(application: Application) : AndroidViewModel(application
 
     init {
         loadAvailableTags()
+        loadNewsletterData()
     }
 
     private fun loadAvailableTags() {
@@ -53,6 +56,55 @@ class ComposerViewModel(application: Application) : AndroidViewModel(application
         }
     }
 
+    private fun loadNewsletterData() {
+        val enabled = newsletterPreferences.isNewsletterEnabled()
+        _uiState.update { it.copy(newsletterEnabled = enabled) }
+        if (enabled) {
+            viewModelScope.launch {
+                // Fetch available newsletters
+                repository.fetchNewsletters().fold(
+                    onSuccess = { newsletters ->
+                        _uiState.update { state ->
+                            state.copy(
+                                availableNewsletters = newsletters,
+                                selectedNewsletter = newsletters.firstOrNull()
+                            )
+                        }
+                    },
+                    onFailure = { /* silently ignore */ }
+                )
+                // Fetch subscriber count (lightweight: limit=1, read meta.pagination.total)
+                repository.fetchSubscriberCount().fold(
+                    onSuccess = { count ->
+                        _uiState.update { it.copy(subscriberCount = count) }
+                    },
+                    onFailure = { /* silently ignore */ }
+                )
+            }
+        }
+    }
+
+    fun toggleSendAsNewsletter() {
+        _uiState.update { it.copy(sendAsNewsletter = !it.sendAsNewsletter) }
+    }
+
+    fun selectNewsletter(newsletter: GhostNewsletter) {
+        _uiState.update { it.copy(selectedNewsletter = newsletter) }
+    }
+
+    fun setEmailSegment(segment: String) {
+        _uiState.update { it.copy(emailSegment = segment) }
+    }
+
+    fun confirmNewsletterSend() {
+        _uiState.update { it.copy(showNewsletterConfirmation = false) }
+        publish()
+    }
+
+    fun cancelNewsletterConfirmation() {
+        _uiState.update { it.copy(showNewsletterConfirmation = false) }
+    }
+
     fun updateTagInput(input: String) {
         val suggestions = if (input.isBlank()) {
             emptyList()
@@ -223,7 +275,15 @@ class ComposerViewModel(application: Application) : AndroidViewModel(application
         _uiState.update { it.copy(featured = !it.featured) }
     }
 
-    fun publish() = submitPost(PostStatus.PUBLISHED, QueueStatus.QUEUED_PUBLISH)
+    fun publish() {
+        val state = _uiState.value
+        if (state.sendAsNewsletter && state.selectedNewsletter != null && !state.showNewsletterConfirmation) {
+            // Show confirmation dialog before sending as newsletter
+            _uiState.update { it.copy(showNewsletterConfirmation = true) }
+            return
+        }
+        submitPost(PostStatus.PUBLISHED, QueueStatus.QUEUED_PUBLISH)
+    }
 
     fun saveDraft() = submitPost(PostStatus.DRAFT, QueueStatus.NONE)
 
@@ -265,7 +325,8 @@ class ComposerViewModel(application: Application) : AndroidViewModel(application
                     linkImageUrl = state.linkPreview?.imageUrl,
                     scheduledAt = state.scheduledAt,
                     tags = tagsJson,
-                    queueStatus = if (status == PostStatus.DRAFT) QueueStatus.NONE else offlineQueueStatus
+                    queueStatus = if (status == PostStatus.DRAFT) QueueStatus.NONE else offlineQueueStatus,
+                    newsletterSlug = if (state.sendAsNewsletter) state.selectedNewsletter?.slug else null
                 )
                 repository.saveLocalPost(localPost)
 
@@ -311,11 +372,17 @@ class ComposerViewModel(application: Application) : AndroidViewModel(application
                 tags = ghostTags.ifEmpty { null }
             )
 
+            // Determine newsletter params
+            val newsletterSlug = if (state.sendAsNewsletter && state.selectedNewsletter != null) {
+                state.selectedNewsletter.slug
+            } else null
+            val emailSeg = if (newsletterSlug != null) state.emailSegment else null
+
             val result = if (editingGhostId != null) {
                 val updatePost = ghostPost.copy(updated_at = editingUpdatedAt)
-                repository.updatePost(editingGhostId!!, updatePost)
+                repository.updatePost(editingGhostId!!, updatePost, newsletter = newsletterSlug, emailSegment = emailSeg)
             } else {
-                repository.createPost(ghostPost)
+                repository.createPost(ghostPost, newsletter = newsletterSlug, emailSegment = emailSeg)
             }
 
             result.fold(
@@ -342,7 +409,8 @@ class ComposerViewModel(application: Application) : AndroidViewModel(application
                         linkImageUrl = state.linkPreview?.imageUrl,
                         scheduledAt = state.scheduledAt,
                         tags = tagsJson,
-                        queueStatus = offlineQueueStatus
+                        queueStatus = offlineQueueStatus,
+                        newsletterSlug = if (state.sendAsNewsletter) state.selectedNewsletter?.slug else null
                     )
                     repository.saveLocalPost(localPost)
                     PostUploadWorker.enqueue(appContext)
@@ -382,7 +450,15 @@ data class ComposerUiState(
     val isEditing: Boolean = false,
     val error: String? = null,
     val isPreviewMode: Boolean = false,
-    val previewHtml: String = ""
+    val previewHtml: String = "",
+    // Newsletter fields
+    val newsletterEnabled: Boolean = false,
+    val availableNewsletters: List<GhostNewsletter> = emptyList(),
+    val selectedNewsletter: GhostNewsletter? = null,
+    val sendAsNewsletter: Boolean = false,
+    val emailSegment: String = "all",
+    val showNewsletterConfirmation: Boolean = false,
+    val subscriberCount: Int? = null
 ) {
     /**
      * Backwards compatibility: returns the first image URI or null.