feat: add email-only post option in Composer with confirmation dialog

Phase 4b.2: Email-only option in Composer.
- Add "Send via Email Only" dropdown menu item (visible when newsletter enabled)
- Add showEmailOnlyConfirmation state to ComposerUiState
- Add sendEmailOnly(), confirmEmailOnly(), cancelEmailOnly() to ViewModel
- submitEmailOnlyPost() saves with emailOnly=true, QUEUED_EMAIL_ONLY status
- Add EmailOnlyConfirmationDialog with warning icon, post preview,
  newsletter picker (if multiple), bold warning about irreversibility,
  and error-colored confirm button

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

@@ -236,6 +236,20 @@ fun ComposerScreen(
                                 enabled = canSubmit
                             )
 
+                            // Email-only option
+                            if (state.newsletterEnabled) {
+                                HorizontalDivider(modifier = Modifier.padding(vertical = 4.dp))
+                                DropdownMenuItem(
+                                    text = { Text("Send via Email Only") },
+                                    onClick = {
+                                        showSendMenu = false
+                                        viewModel.sendEmailOnly()
+                                    },
+                                    leadingIcon = { Icon(Icons.Default.Email, null) },
+                                    enabled = canSubmit
+                                )
+                            }
+
                             // Newsletter options
                             if (state.newsletterEnabled) {
                                 HorizontalDivider(modifier = Modifier.padding(vertical = 4.dp))
@@ -769,6 +783,18 @@ fun ComposerScreen(
             onDismiss = viewModel::cancelNewsletterConfirmation
         )
     }
+
+    // Email-only confirmation dialog
+    if (state.showEmailOnlyConfirmation) {
+        EmailOnlyConfirmationDialog(
+            postPreview = state.text.take(80),
+            availableNewsletters = state.availableNewsletters,
+            selectedNewsletter = state.selectedNewsletter,
+            onSelectNewsletter = viewModel::selectNewsletter,
+            onConfirm = viewModel::confirmEmailOnly,
+            onDismiss = viewModel::cancelEmailOnly
+        )
+    }
 }
 
 /**
@@ -1011,6 +1037,119 @@ fun NewsletterConfirmationDialog(
     )
 }
 
+/**
+ * Confirmation dialog for email-only sending.
+ * Shows a warning that the post will NOT appear on the blog.
+ */
+@Composable
+fun EmailOnlyConfirmationDialog(
+    postPreview: String,
+    availableNewsletters: List<GhostNewsletter>,
+    selectedNewsletter: GhostNewsletter?,
+    onSelectNewsletter: (GhostNewsletter) -> Unit,
+    onConfirm: () -> Unit,
+    onDismiss: () -> Unit
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        icon = {
+            Icon(
+                Icons.Default.Warning,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.error,
+                modifier = Modifier.size(32.dp)
+            )
+        },
+        title = {
+            Text(
+                text = "Send via email only?",
+                style = MaterialTheme.typography.titleMedium
+            )
+        },
+        text = {
+            Column {
+                // Post content preview
+                if (postPreview.isNotBlank()) {
+                    OutlinedCard(modifier = Modifier.fillMaxWidth()) {
+                        Text(
+                            text = postPreview + if (postPreview.length >= 80) "..." else "",
+                            style = MaterialTheme.typography.bodySmall,
+                            modifier = Modifier.padding(12.dp),
+                            maxLines = 3,
+                            overflow = TextOverflow.Ellipsis
+                        )
+                    }
+                    Spacer(modifier = Modifier.height(12.dp))
+                }
+
+                // Newsletter picker (only if multiple)
+                if (availableNewsletters.size > 1) {
+                    Text(
+                        text = "Newsletter:",
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                    Column(modifier = Modifier.selectableGroup()) {
+                        availableNewsletters.forEach { newsletter ->
+                            Row(
+                                modifier = Modifier
+                                    .fillMaxWidth()
+                                    .selectable(
+                                        selected = selectedNewsletter?.id == newsletter.id,
+                                        onClick = { onSelectNewsletter(newsletter) }
+                                    )
+                                    .padding(vertical = 4.dp),
+                                verticalAlignment = Alignment.CenterVertically
+                            ) {
+                                RadioButton(
+                                    selected = selectedNewsletter?.id == newsletter.id,
+                                    onClick = { onSelectNewsletter(newsletter) }
+                                )
+                                Text(
+                                    text = newsletter.name,
+                                    style = MaterialTheme.typography.bodySmall,
+                                    modifier = Modifier.padding(start = 4.dp)
+                                )
+                            }
+                        }
+                    }
+                    Spacer(modifier = Modifier.height(12.dp))
+                } else if (selectedNewsletter != null) {
+                    Text(
+                        text = "Newsletter: ${selectedNewsletter.name}",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                    Spacer(modifier = Modifier.height(12.dp))
+                }
+
+                // Bold warning
+                Text(
+                    text = "This cannot be undone. Post will NOT appear on blog.",
+                    style = MaterialTheme.typography.bodySmall.copy(fontWeight = FontWeight.Bold),
+                    color = MaterialTheme.colorScheme.error
+                )
+            }
+        },
+        confirmButton = {
+            Button(
+                onClick = onConfirm,
+                colors = ButtonDefaults.buttonColors(
+                    containerColor = MaterialTheme.colorScheme.error,
+                    contentColor = MaterialTheme.colorScheme.onError
+                )
+            ) {
+                Text("\u2709 SEND EMAIL")
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text("Cancel")
+            }
+        }
+    )
+}
+
 /**
  * Displays a 2-column grid of image thumbnails with remove buttons.
  * Includes an "Add more" button at the end.

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

@@ -105,6 +105,62 @@ class ComposerViewModel(application: Application) : AndroidViewModel(application
         _uiState.update { it.copy(showNewsletterConfirmation = false) }
     }
 
+    fun sendEmailOnly() {
+        _uiState.update { it.copy(showEmailOnlyConfirmation = true) }
+    }
+
+    fun confirmEmailOnly() {
+        _uiState.update { it.copy(showEmailOnlyConfirmation = false) }
+        submitEmailOnlyPost()
+    }
+
+    fun cancelEmailOnly() {
+        _uiState.update { it.copy(showEmailOnlyConfirmation = false) }
+    }
+
+    private fun submitEmailOnlyPost() {
+        val state = _uiState.value
+        if (state.text.isBlank() && state.imageUris.isEmpty() && state.fileUri == null) return
+
+        viewModelScope.launch {
+            _uiState.update { it.copy(isSubmitting = true, error = null) }
+
+            val title = state.text.take(60)
+            val hashtagTags = HashtagParser.parse(state.text)
+            val allTags = (state.extractedTags + hashtagTags).distinctBy { it.lowercase() }
+            val tagsJson = Gson().toJson(allTags)
+            val altText = state.imageAlt.ifBlank { null }
+            val newsletterSlug = state.selectedNewsletter?.slug
+
+            // Save locally and queue for upload
+            val localPost = LocalPost(
+                localId = editingLocalId ?: 0,
+                ghostId = editingGhostId,
+                title = title,
+                content = state.text,
+                status = PostStatus.PUBLISHED,
+                featured = false,
+                imageUri = state.imageUris.firstOrNull()?.toString(),
+                imageUris = Converters.stringListToJson(state.imageUris.map { it.toString() }),
+                imageAlt = altText,
+                linkUrl = state.linkPreview?.url,
+                linkTitle = state.linkPreview?.title,
+                linkDescription = state.linkPreview?.description,
+                linkImageUrl = state.linkPreview?.imageUrl,
+                tags = tagsJson,
+                queueStatus = QueueStatus.QUEUED_EMAIL_ONLY,
+                emailOnly = true,
+                newsletterSlug = newsletterSlug,
+                fileUri = state.fileUri?.toString(),
+                fileName = state.fileName
+            )
+            repository.saveLocalPost(localPost)
+            PostUploadWorker.enqueue(appContext)
+
+            _uiState.update { it.copy(isSubmitting = false, isSuccess = true) }
+        }
+    }
+
     fun updateTagInput(input: String) {
         val suggestions = if (input.isBlank()) {
             emptyList()
@@ -536,7 +592,9 @@ data class ComposerUiState(
     val sendAsNewsletter: Boolean = false,
     val emailSegment: String = "all",
     val showNewsletterConfirmation: Boolean = false,
-    val subscriberCount: Int? = null
+    val subscriberCount: Int? = null,
+    // Email-only
+    val showEmailOnlyConfirmation: Boolean = false
 ) {
     /**
      * Backwards compatibility: returns the first image URI or null.