feat(settings): grouped sidebar matching Outline's own settings categories

SettingsSection now carries a SettingsCategory (general/account/
workspace/integrationsInstallation) and SettingsSidebarList renders it
as a grouped, headered list — general (ours: Appearance, Offline &
Sync, Advanced, About) unlabeled at the top, then Account (Profile,
Preferences, Notifications, Passkeys, API & Access), Workspace
(Details, Authentication, Security, AI, Members, Groups, Templates,
Emojis, Applications, Shared, Links, Webhooks, Import, Export), and
Integrations & Installation (Installation).

Nav skeleton only, per instruction — everything except the ones
already built (renamed the old flat "Account" page to "Profile", its
natural new home; content unchanged) shows a "Coming Soon" placeholder
until each section's real content is specified and built one at a
time.

Outpost/Features/Account/SettingsSidebarList.swift

@@ -6,6 +6,10 @@ import SwiftUI
 /// content, rather than a separate mini sidebar nested inside a page. "Done"
 /// clears `AppNavigation.isShowingSettings`, which puts the collections tree
 /// back.
+///
+/// Grouped by `SettingsCategory` — `general` (ours) sits unlabeled at the
+/// top, then Outline's own Account/Workspace/Integrations & Installation
+/// groups, matching the settings page structure of the Outline web app.
 struct SettingsSidebarList: View {
     @Binding var selection: SettingsSection?
     let onDone: () -> Void
@@ -22,10 +26,21 @@ struct SettingsSidebarList: View {
 
             Divider()
 
-            List(SettingsSection.allCases, selection: $selection) { section in
+            List(selection: $selection) {
+                ForEach(SettingsCategory.allCases) { category in
+                    let sections = SettingsSection.allCases.filter { $0.category == category }
+                    Section {
+                        ForEach(sections) { section in
                             Label(section.title, systemImage: section.icon)
                                 .tag(section)
                         }
+                    } header: {
+                        if let title = category.title {
+                            Text(title)
+                        }
+                    }
+                }
+            }
             .listStyle(.sidebar)
 
             Divider()

Outpost/Features/Account/SettingsView.swift

@@ -62,13 +62,29 @@ struct SettingsView: View {
     private var sectionDetail: some View {
         switch section {
         case .appearance: appearanceDetail
-        case .account: accountDetail
+        case .profile: profileDetail
         case .offlineSync: offlineSyncDetail
         case .advanced: advancedDetail
         case .about: aboutDetail
+        default: comingSoonDetail
         }
     }
 
+    /// Everything in Account/Workspace/Integrations & Installation that
+    /// isn't `.profile` — real content lands section by section; this is
+    /// just the nav skeleton until then.
+    private var comingSoonDetail: some View {
+        VStack(spacing: 16) {
+            sectionHeader
+            ContentUnavailableView {
+                Label("Coming Soon", systemImage: section.icon)
+            } description: {
+                Text("\(section.title) settings aren't built yet.")
+            }
+        }
+        .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .center)
+    }
+
     private var sectionHeader: some View {
         Text(section.title)
             .font(.title.bold())
@@ -90,9 +106,9 @@ struct SettingsView: View {
         }
     }
 
-    // MARK: - Account
+    // MARK: - Profile
 
-    private var accountDetail: some View {
+    private var profileDetail: some View {
         VStack(alignment: .leading, spacing: 16) {
             sectionHeader
             VStack(alignment: .leading, spacing: 10) {

Outpost/Root/AppNavigation.swift

@@ -1,27 +1,130 @@
 import Observation
 
-enum SettingsSection: String, CaseIterable, Identifiable, Hashable {
+/// Top-level groupings shown as section headers in `SettingsSidebarList`.
-    case appearance, account, offlineSync, advanced, about
+/// `general` holds everything that's ours, not Outline's own settings
+/// categories — no header, sits above the named groups.
+enum SettingsCategory: String, CaseIterable, Identifiable {
+    case general
+    case account
+    case workspace
+    case integrationsInstallation
 
     var id: String { rawValue }
 
+    var title: String? {
+        switch self {
+        case .general: return nil
+        case .account: return "Account"
+        case .workspace: return "Workspace"
+        case .integrationsInstallation: return "Integrations & Installation"
+        }
+    }
+}
+
+/// One entry in the Settings sidebar. Mirrors Outline's own settings
+/// categories (Account/Workspace/Integrations & Installation) so this app's
+/// settings read as a native counterpart to the web app's, plus a `general`
+/// group for things that are ours and don't map onto Outline's structure
+/// (offline/sync, advanced, about, appearance).
+///
+/// Most of the Account/Workspace/Integrations cases are navigation-only for
+/// now — `SettingsView` renders a "Coming Soon" placeholder for anything not
+/// explicitly built yet. Content lands section by section.
+enum SettingsSection: String, CaseIterable, Identifiable, Hashable {
+    // General (ours)
+    case appearance, offlineSync, advanced, about
+
+    // Account
+    case profile, preferences, notifications, passkeys, apiAccess
+
+    // Workspace
+    case details, authentication, security, ai, members, groups, templates, emojis, applications, shared, links, webhooks, importData, exportData
+
+    // Integrations & Installation
+    case installation
+
+    var id: String { rawValue }
+
+    var category: SettingsCategory {
+        switch self {
+        case .appearance, .offlineSync, .advanced, .about:
+            return .general
+        case .profile, .preferences, .notifications, .passkeys, .apiAccess:
+            return .account
+        case .details, .authentication, .security, .ai, .members, .groups, .templates, .emojis, .applications, .shared, .links, .webhooks, .importData, .exportData:
+            return .workspace
+        case .installation:
+            return .integrationsInstallation
+        }
+    }
+
     var title: String {
         switch self {
         case .appearance: return "Appearance"
-        case .account: return "Account"
         case .offlineSync: return "Offline & Sync"
         case .advanced: return "Advanced"
         case .about: return "About"
+        case .profile: return "Profile"
+        case .preferences: return "Preferences"
+        case .notifications: return "Notifications"
+        case .passkeys: return "Passkeys"
+        case .apiAccess: return "API & Access"
+        case .details: return "Details"
+        case .authentication: return "Authentication"
+        case .security: return "Security"
+        case .ai: return "AI"
+        case .members: return "Members"
+        case .groups: return "Groups"
+        case .templates: return "Templates"
+        case .emojis: return "Emojis"
+        case .applications: return "Applications"
+        case .shared: return "Shared"
+        case .links: return "Links"
+        case .webhooks: return "Webhooks"
+        case .importData: return "Import"
+        case .exportData: return "Export"
+        case .installation: return "Installation"
         }
     }
 
     var icon: String {
         switch self {
         case .appearance: return "paintbrush"
-        case .account: return "person.crop.circle"
         case .offlineSync: return "arrow.triangle.2.circlepath"
         case .advanced: return "wrench.and.screwdriver"
         case .about: return "info.circle"
+        case .profile: return "person.crop.circle"
+        case .preferences: return "gearshape"
+        case .notifications: return "bell"
+        case .passkeys: return "key"
+        case .apiAccess: return "chevron.left.forwardslash.chevron.right"
+        case .details: return "building.2"
+        case .authentication: return "lock"
+        case .security: return "shield"
+        case .ai: return "sparkles"
+        case .members: return "person.2"
+        case .groups: return "person.3"
+        case .templates: return "doc.on.doc"
+        case .emojis: return "face.smiling"
+        case .applications: return "app.badge"
+        case .shared: return "square.and.arrow.up.on.square"
+        case .links: return "link"
+        case .webhooks: return "bolt.horizontal"
+        case .importData: return "square.and.arrow.down"
+        case .exportData: return "square.and.arrow.up"
+        case .installation: return "shippingbox"
+        }
+    }
+
+    /// Everything actually built so far — everything else in Account/
+    /// Workspace/Integrations & Installation renders a "Coming Soon"
+    /// placeholder until its content is specified and built.
+    var isImplemented: Bool {
+        switch self {
+        case .appearance, .offlineSync, .advanced, .about, .profile:
+            return true
+        default:
+            return false
         }
     }
 }