feat(settings): Preferences delete-account action

Danger subsection, confirmation dialog before calling users.delete
(deleteAccount()), signs out locally on success. Closes out the
Preferences page.

Outpost/Features/Account/SettingsView.swift

@@ -36,6 +36,9 @@ struct SettingsView: View {
     @State private var languageErrorMessage: String?
     @State private var isSavingPreferences = false
     @State private var preferencesErrorMessage: String?
+    @State private var isShowingDeleteAccountConfirmation = false
+    @State private var isDeletingAccount = false
+    @State private var deleteAccountErrorMessage: String?
 
     /// Full Local Sync and cache-clearing both need a real connection to be
     /// safe — clearing while offline (or letting Full Local Sync think it
@@ -302,9 +305,49 @@ struct SettingsView: View {
                     .font(.caption)
                     .foregroundStyle(.red)
             }
+
+            preferencesSubsection("Danger") {
+                deleteAccountRow
+            }
         }
         .frame(maxWidth: 480, alignment: .leading)
         .task { await refreshProfile() }
+        .confirmationDialog(
+            "Delete Account?",
+            isPresented: $isShowingDeleteAccountConfirmation,
+            titleVisibility: .visible
+        ) {
+            Button("Delete Account", role: .destructive) { Task { await deleteAccount() } }
+            Button("Cancel", role: .cancel) {}
+        } message: {
+            Text("This is unrecoverable — everything associated with your account will be permanently deleted.")
+        }
+    }
+
+    private var deleteAccountRow: some View {
+        VStack(alignment: .leading, spacing: 6) {
+            HStack {
+                VStack(alignment: .leading, spacing: 2) {
+                    Text("Delete account")
+                    Text("You may delete your account at any time, note that this is unrecoverable.")
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                }
+                Spacer()
+                if isDeletingAccount {
+                    ProgressView().controlSize(.small)
+                } else {
+                    Button("Delete…", role: .destructive) { isShowingDeleteAccountConfirmation = true }
+                        .buttonStyle(.bordered)
+                        .tint(.red)
+                }
+            }
+            if let deleteAccountErrorMessage {
+                Text(deleteAccountErrorMessage)
+                    .font(.caption)
+                    .foregroundStyle(.red)
+            }
+        }
     }
 
     private func preferencesSubsection<Content: View>(
@@ -407,6 +450,18 @@ struct SettingsView: View {
         )
     }
 
+    private func deleteAccount() async {
+        guard let apiClient = session.apiClient else { return }
+        isDeletingAccount = true
+        defer { isDeletingAccount = false }
+        do {
+            try await apiClient.deleteAccount()
+            session.signOut()
+        } catch {
+            deleteAccountErrorMessage = outlineErrorMessage(error, fallback: "Couldn't delete your account.")
+        }
+    }
+
     private func saveLanguage(_ code: String) async {
         guard code != session.userLanguage, let apiClient = session.apiClient, let userId = session.userId else { return }
         isSavingLanguage = true