feat: more native menus with expected reactions

PLAN.md

@@ -4,23 +4,7 @@ Only unfinished implementation work belongs here. DwarfStar remains the
 behavioral oracle for model execution, token processing, context accounting,
 KV-cache behavior, the HTTP API, and the built-in agent loop.
 
-## 1. Finish native project and chat controls
+## 1. Add Dev Brain support
-
-- Add functional File, View, and Help menus; update native menu enabled state
-  from the focused control; complete undo/redo behavior; and make transcript
-  text selectable and copyable.
-- File menu has an "export" menu to save a chat as markdown
-- File menu has a new "menu" that opens a new chat in the currently active
-  project. if the app is not on a project or session of a project in the
-  sidebar, "new" is disabled
-- View menu gets the "manage models" menu item, remove it from Window menu
-- View menu gets toggle menu for sidebar with hotkey cmd-B
-- Explain model/checkpoint mismatches where a session must rebuild context
-  instead of resuming its existing checkpoint.
-- the hellp menu must open a window with an actual documentation in it,
-  that still needs to be constructed from the information and implementation
-
-## 2. Add Dev Brain support
 
 - Let the user select one Obsidian vault and give the local agent bounded
   Markdown memory_search, memory_read, memory_create, and memory_append

docs/USER_GUIDE.md

@@ -0,0 +1,78 @@
+# DS4Server Help
+
+DS4Server runs supported DwarfStar language models locally on your Mac. Chats,
+project references, and settings stay on this computer.
+
+## Projects and chats
+
+Choose **Add project** to give the coding agent access to a folder. The agent's
+file tools are bounded to that project. Use **File > New Chat** (`⌘N`) to start
+a chat in the active project. Chats are saved after their first message and can
+be renamed, pinned, archived, compacted, rebuilt, or deleted from the sidebar.
+
+Use **File > Export Chat as Markdown** (`⇧⌘S`) to save the visible conversation,
+including reasoning and tool results. System-only messages are omitted.
+
+## Writing and editing
+
+Enter a prompt at the bottom of the Chat view. While a response is running,
+additional prompts are queued. **Stop** cancels generation and active agent
+work. The Edit menu follows the focused text control and supports undo, redo,
+cut, copy, paste, and select all. Transcript text can be selected and copied.
+
+The context indicator beside the composer shows used and available tokens.
+DS4Server automatically compacts long chats near the context limit; the full
+visible transcript remains available.
+
+## Checkpoints and model changes
+
+Each saved chat keeps a local KV checkpoint so its next turn can resume without
+prefilling the whole conversation. A checkpoint belongs to the exact model,
+quantization, context size, and executor configuration that created it.
+
+If the selected model, model file, quantization, context size, or relevant
+runtime configuration changes, DS4Server cannot safely resume that checkpoint.
+It reports that the context is being rebuilt, prefills the saved transcript,
+and writes a compatible replacement. No chat messages are lost. **Rebuild
+context on next use** performs the same safe rebuild manually.
+
+## Models
+
+Open **View > Model Manager** (`⇧⌘M`) to download, resume, verify, or remove
+supported model artifacts. Preferences choose the active model and control
+generation, context, speculative decoding, Metal execution, SSD expert
+streaming, steering, checkpoint storage, diagnostics, and the local endpoint.
+
+Model files are large. Verification checks the complete artifact before it is
+used. Removing a model never removes projects or chat history.
+
+## Agent tools and approvals
+
+The local agent can inspect and edit project files, search text, and run shell
+commands. Operations that can affect data outside the ordinary project workflow
+show an approval dialog. Read the command and working directory before choosing
+**Allow once**. Choose **Deny** to return the refusal to the agent.
+
+Tool calls and results appear in the transcript. Use their copy actions for the
+complete, untruncated text; large outputs can also be opened from their saved
+file.
+
+## Views and sidebar
+
+Use **View > Show Sidebar** (`⌘B`) to hide or restore the project sidebar. The
+Chat view shows the transcript, A2UI shows the latest interactive surface, and
+Stats reports model, generation, HTTP, SSD, and KV-cache activity.
+
+## Local HTTP endpoint
+
+Preferences can enable an OpenAI- and Anthropic-compatible endpoint on
+`127.0.0.1` (port `4000` by default). Endpoint conversations are owned by their
+client and do not appear in the project sidebar. CORS is off by default and
+should only be enabled for trusted local browser clients.
+
+## Data and recovery
+
+Application data is stored under `~/Library/Application Support/de.rfc1437.ds4server/`.
+Deleting a project from DS4Server removes its saved sessions and checkpoints,
+but never deletes the referenced project folder. Deleting a session removes its
+transcript and checkpoint permanently.

src/app.rs

@@ -47,11 +47,14 @@ pub(super) const MAX_SIDEBAR_WIDTH: i32 = 520;
 pub(crate) struct App {
     main_window: window::Id,
     pub(super) model_manager_window: Option<window::Id>,
+    pub(super) help_window: Option<window::Id>,
     pub(super) pending_model_delete: Option<ManagedArtifactId>,
     #[cfg(target_os = "macos")]
     _native_menu: Option<crate::native_menu::NativeMenu>,
     #[cfg(target_os = "macos")]
     pub(super) native_edit_commands: crate::native_edit::EditCommandQueue,
+    #[cfg(target_os = "macos")]
+    pub(super) native_edit_availability: crate::native_edit::EditAvailabilityState,
     database: Option<Database>,
     projects: Vec<ProjectWithSessions>,
     config: Config,
@@ -87,6 +90,7 @@ pub(crate) struct App {
     pub(super) a2ui_modals: HashSet<(String, String)>,
     pub(super) a2ui_editors: HashMap<(String, String, String), text_editor::Content>,
     pub(super) a2ui_markdown: HashMap<(String, String, String), markdown::Content>,
+    pub(super) help_markdown: markdown::Content,
     pub(super) a2ui_choice_filters: HashMap<(String, String, String), String>,
     pub(super) a2ui_images: HashMap<String, iced::widget::image::Handle>,
     pub(super) a2ui_image_requests: HashSet<String>,
@@ -133,6 +137,7 @@ pub(crate) struct App {
     _endpoint: Option<crate::server::ServerHandle>,
     error: Option<String>,
     pub(super) activity: Option<String>,
+    pub(super) context_notice: Option<String>,
     stop_requested: bool,
     system_prompt_seen_at: u32,
     manual_compaction_queued: bool,
@@ -167,6 +172,11 @@ pub(crate) enum Message {
     NativeEdit(crate::native_edit::EditCommand),
     OpenPreferences,
     OpenModelManager,
+    OpenHelp,
+    HelpOpened(window::Id),
+    NewChat,
+    ExportChat,
+    ExportChatPicked(Option<PathBuf>),
     ModelManagerOpened(window::Id),
     WindowOpened(window::Id),
     WindowClosed(window::Id),
@@ -238,6 +248,7 @@ pub(crate) enum Message {
     StopModelDownload,
     DownloadProgressTick,
     ComposerChanged(String),
+    TranscriptAction(usize, text_editor::Action),
     ToggleReasoning(usize),
     OpenLink(markdown::Uri),
     CopyToolText(String),
@@ -315,11 +326,14 @@ impl App {
                     Self {
                         main_window,
                         model_manager_window: None,
+                        help_window: None,
                         pending_model_delete: None,
                         #[cfg(target_os = "macos")]
                         _native_menu: None,
                         #[cfg(target_os = "macos")]
                         native_edit_commands: crate::native_edit::command_queue(),
+                        #[cfg(target_os = "macos")]
+                        native_edit_availability: crate::native_edit::availability_state(),
                         database: Some(database),
                         projects,
                         config,
@@ -348,6 +362,9 @@ impl App {
                         a2ui_modals: HashSet::new(),
                         a2ui_editors: HashMap::new(),
                         a2ui_markdown: HashMap::new(),
+                        help_markdown: markdown::Content::parse(include_str!(
+                            "../docs/USER_GUIDE.md"
+                        )),
                         a2ui_choice_filters: HashMap::new(),
                         a2ui_images: HashMap::new(),
                         a2ui_image_requests: HashSet::new(),
@@ -400,6 +417,7 @@ impl App {
                             }
                         },
                         activity: None,
+                        context_notice: None,
                         stop_requested: false,
                         system_prompt_seen_at: 0,
                         manual_compaction_queued: false,
@@ -435,11 +453,14 @@ impl App {
         Self {
             main_window,
             model_manager_window: None,
+            help_window: None,
             pending_model_delete: None,
             #[cfg(target_os = "macos")]
             _native_menu: None,
             #[cfg(target_os = "macos")]
             native_edit_commands: crate::native_edit::command_queue(),
+            #[cfg(target_os = "macos")]
+            native_edit_availability: crate::native_edit::availability_state(),
             database: None,
             projects: Vec::new(),
             config,
@@ -468,6 +489,7 @@ impl App {
             a2ui_modals: HashSet::new(),
             a2ui_editors: HashMap::new(),
             a2ui_markdown: HashMap::new(),
+            help_markdown: markdown::Content::parse(include_str!("../docs/USER_GUIDE.md")),
             a2ui_choice_filters: HashMap::new(),
             a2ui_images: HashMap::new(),
             a2ui_image_requests: HashSet::new(),
@@ -514,6 +536,7 @@ impl App {
                 None => error,
             }),
             activity: None,
+            context_notice: None,
             stop_requested: false,
             system_prompt_seen_at: 0,
             manual_compaction_queued: false,
@@ -524,13 +547,54 @@ impl App {
 
     pub(crate) fn update(&mut self, message: Message) -> Task<Message> {
         match message {
-            Message::Noop => {}
+            Message::Noop => {
+                #[cfg(target_os = "macos")]
+                self.sync_native_menu();
+            }
             #[cfg(target_os = "macos")]
             Message::NativeEdit(command) => {
                 crate::native_edit::queue_command(&self.native_edit_commands, command)
             }
             Message::OpenPreferences => self.open_preferences(),
             Message::OpenModelManager => return self.open_model_manager(),
+            Message::OpenHelp => return self.open_help(),
+            Message::HelpOpened(id) => {
+                if self.help_window == Some(id) {
+                    return window::gain_focus(id);
+                }
+            }
+            Message::NewChat => {
+                if let Some(project_id) = self.selected_project {
+                    self.create_session(project_id);
+                    return focus_composer();
+                }
+            }
+            Message::ExportChat => {
+                let Some(title) = self.active_chat_title().map(str::to_owned) else {
+                    return Task::none();
+                };
+                let file_name = format!("{}.md", export_file_stem(&title));
+                return Task::perform(
+                    async move {
+                        AsyncFileDialog::new()
+                            .set_title("Export chat as Markdown")
+                            .set_file_name(&file_name)
+                            .add_filter("Markdown", &["md"])
+                            .save_file()
+                            .await
+                            .map(|file| file.path().to_path_buf())
+                    },
+                    Message::ExportChatPicked,
+                );
+            }
+            Message::ExportChatPicked(path) => {
+                if let Some(path) = path
+                    && let Some(title) = self.active_chat_title()
+                    && let Err(error) = fs::write(&path, export_markdown(title, &self.conversation))
+                {
+                    self.error = Some(format!("Could not export the chat: {error}"));
+                }
+            }
             Message::ModelManagerOpened(id) => {
                 if self.model_manager_window == Some(id) {
                     return window::gain_focus(id);
@@ -547,6 +611,8 @@ impl App {
                         }
                     }
                 }
+                #[cfg(target_os = "macos")]
+                self.sync_native_menu();
                 if id == self.main_window && self.selected_project.is_some() {
                     return focus_composer();
                 }
@@ -559,6 +625,9 @@ impl App {
                     self.model_manager_window = None;
                     self.pending_model_delete = None;
                 }
+                if self.help_window == Some(id) {
+                    self.help_window = None;
+                }
             }
             Message::DismissPanel => {
                 if self.pending_session_delete.is_some() {
@@ -612,6 +681,8 @@ impl App {
             Message::ToggleSidebar => {
                 self.config.interface.sidebar_collapsed = !self.config.interface.sidebar_collapsed;
                 self.store_config();
+                #[cfg(target_os = "macos")]
+                self.sync_native_menu();
             }
             Message::MetricsTick => self.sample_metrics(),
             Message::PreferenceModelChanged(model) => {
@@ -873,6 +944,13 @@ impl App {
             }
             Message::DownloadProgressTick => self.update_download_progress(),
             Message::ComposerChanged(value) => self.composer = value,
+            Message::TranscriptAction(index, action) => {
+                if !action.is_edit()
+                    && let Some(message) = self.conversation.get_mut(index)
+                {
+                    message.transcript.perform(action);
+                }
+            }
             Message::A2uiDataChanged(surface_id, path, value) => {
                 if self.a2ui_history_index.is_some() {
                     return Task::none();
@@ -1158,6 +1236,7 @@ impl App {
                                 self.selected_project = None;
                                 self.selected_session = None;
                                 self.conversation.clear();
+                                self.context_notice = None;
                                 self.clear_a2ui();
                                 self.composer.clear();
                                 self.queued_inputs.clear();
@@ -1321,6 +1400,7 @@ impl App {
                 match loaded {
                     Ok((messages, a2ui)) => {
                         self.conversation = messages.into_iter().map(ChatMessage::from).collect();
+                        self.context_notice = None;
                         self.clear_a2ui();
                         let (history, active, errors) =
                             crate::a2ui::replay_epochs(a2ui.iter().map(|message| {
@@ -1403,6 +1483,7 @@ impl App {
                             if self.selected_session == Some(session_id) {
                                 self.selected_session = None;
                                 self.conversation.clear();
+                                self.context_notice = None;
                                 self.clear_a2ui();
                                 self.composer.clear();
                                 self.queued_inputs.clear();
@@ -1450,6 +1531,10 @@ impl App {
                 Some(crate::native_menu::NativeMenuEvent::ModelManager) => {
                     Message::OpenModelManager
                 }
+                Some(crate::native_menu::NativeMenuEvent::NewChat) => Message::NewChat,
+                Some(crate::native_menu::NativeMenuEvent::ExportChat) => Message::ExportChat,
+                Some(crate::native_menu::NativeMenuEvent::ToggleSidebar) => Message::ToggleSidebar,
+                Some(crate::native_menu::NativeMenuEvent::Help) => Message::OpenHelp,
                 Some(crate::native_menu::NativeMenuEvent::Edit(command)) => {
                     Message::NativeEdit(command)
                 }
@@ -1489,6 +1574,8 @@ impl App {
     pub(crate) fn title(&self, id: window::Id) -> String {
         if self.model_manager_window == Some(id) {
             "Model Manager — DS4Server".to_owned()
+        } else if self.help_window == Some(id) {
+            "Help — DS4Server".to_owned()
         } else {
             "DS4Server".to_owned()
         }
@@ -1594,6 +1681,50 @@ impl App {
         self.kv_cache_report = crate::metrics::kv_cache_report(&kv_cache_path(), budget);
         self.last_cache_scan = Instant::now();
     }
+
+    fn active_chat_title(&self) -> Option<&str> {
+        let project_id = self.selected_project?;
+        if let Some(session_id) = self.selected_session {
+            return self
+                .projects
+                .iter()
+                .flat_map(|project| &project.sessions)
+                .find(|session| session.id == session_id)
+                .map(|session| session.title.as_str());
+        }
+        self.drafts.get(&project_id).map(String::as_str)
+    }
+
+    fn open_help(&mut self) -> Task<Message> {
+        if let Some(id) = self.help_window {
+            return window::gain_focus(id);
+        }
+        let (id, open) = window::open(window::Settings {
+            size: Size::new(760.0, 640.0),
+            min_size: Some(Size::new(560.0, 420.0)),
+            icon: Some(app_icon()),
+            ..Default::default()
+        });
+        self.help_window = Some(id);
+        open.map(Message::HelpOpened)
+    }
+
+    #[cfg(target_os = "macos")]
+    fn sync_native_menu(&self) {
+        let Some(menu) = &self._native_menu else {
+            return;
+        };
+        let edit = *self
+            .native_edit_availability
+            .lock()
+            .unwrap_or_else(|poisoned| poisoned.into_inner());
+        menu.update(
+            self.selected_project.is_some() && !self.generating,
+            self.active_chat_title().is_some(),
+            !self.config.interface.sidebar_collapsed,
+            edit,
+        );
+    }
 }
 
 #[cfg(target_os = "macos")]
@@ -1655,6 +1786,8 @@ fn shortcut(key: keyboard::Key, modifiers: keyboard::Modifiers) -> Option<Messag
         keyboard::Key::Character("m") if modifiers.command() && modifiers.shift() => {
             Some(Message::OpenModelManager)
         }
+        keyboard::Key::Character("b") if modifiers.command() => Some(Message::ToggleSidebar),
+        keyboard::Key::Character("n") if modifiers.command() => Some(Message::NewChat),
         keyboard::Key::Named(keyboard::key::Named::Tab) => Some(if modifiers.shift() {
             Message::FocusPrevious
         } else {
@@ -1664,6 +1797,59 @@ fn shortcut(key: keyboard::Key, modifiers: keyboard::Modifiers) -> Option<Messag
     }
 }
 
+fn export_file_stem(title: &str) -> String {
+    let stem = title
+        .chars()
+        .map(|character| match character {
+            '/' | ':' | '\0' => '-',
+            character => character,
+        })
+        .collect::<String>();
+    let stem = stem.trim().trim_matches('.');
+    if stem.is_empty() {
+        "DS4Server Chat".to_owned()
+    } else {
+        stem.to_owned()
+    }
+}
+
+fn export_markdown(title: &str, conversation: &[ChatMessage]) -> String {
+    use std::fmt::Write;
+
+    let mut output = format!("# {title}\n");
+    for message in conversation {
+        if message.system {
+            continue;
+        }
+        if message.compaction {
+            let _ = write!(
+                output,
+                "\n> Context compacted: {}\n",
+                message.content.trim()
+            );
+            continue;
+        }
+        let label = if message.user {
+            "You"
+        } else if message.tool {
+            "Tool"
+        } else {
+            "DS4"
+        };
+        let _ = write!(output, "\n## {label}\n");
+        if let Some(reasoning) = message.reasoning.as_deref().filter(|text| !text.is_empty()) {
+            let _ = write!(
+                output,
+                "\n<details>\n<summary>Reasoning</summary>\n\n{reasoning}\n\n</details>\n"
+            );
+        }
+        let visible = crate::agent::visible_content(&message.content);
+        let visible = crate::a2ui::transcript_fallback(visible);
+        let _ = write!(output, "\n{}\n", visible.trim());
+    }
+    output
+}
+
 fn application_support_path() -> PathBuf {
     std::env::var_os("HOME")
         .map(PathBuf::from)
@@ -1991,6 +2177,7 @@ mod tests {
             reasoning_open: true,
             content: String::new(),
             markdown: markdown::Content::new(),
+            transcript: text_editor::Content::new(),
             a2ui_lines_processed: 0,
             a2ui_errors: Vec::new(),
             a2ui_replies: Vec::new(),
@@ -2004,4 +2191,40 @@ mod tests {
         assert_eq!(message.content, "**final answer**");
         assert!(!message.markdown.items().is_empty());
     }
+
+    #[test]
+    fn chat_export_keeps_visible_turns_and_omits_system_messages() {
+        let message = |user, tool, system, content: &str| ChatMessage {
+            id: 1,
+            user,
+            tool,
+            system,
+            compaction: false,
+            compaction_tail_start: None,
+            generation_stats: None,
+            reasoning: None,
+            reasoning_complete: true,
+            reasoning_open: false,
+            content: content.into(),
+            markdown: markdown::Content::new(),
+            transcript: text_editor::Content::new(),
+            a2ui_lines_processed: 0,
+            a2ui_errors: Vec::new(),
+            a2ui_replies: Vec::new(),
+            a2ui_open_urls: Vec::new(),
+        };
+        let exported = export_markdown(
+            "A chat",
+            &[
+                message(false, false, true, "private"),
+                message(true, false, false, "hello"),
+                message(false, false, false, "**hi**"),
+            ],
+        );
+        assert_eq!(
+            exported,
+            "# A chat\n\n## You\n\nhello\n\n## DS4\n\n**hi**\n"
+        );
+        assert!(!exported.contains("private"));
+    }
 }

src/app/generation.rs

@@ -61,6 +61,7 @@ pub(crate) struct ChatMessage {
     pub(super) reasoning_open: bool,
     pub(super) content: String,
     pub(super) markdown: markdown::Content,
+    pub(super) transcript: text_editor::Content,
     pub(super) a2ui_lines_processed: usize,
     pub(super) a2ui_errors: Vec<String>,
     pub(super) a2ui_replies: Vec<serde_json::Value>,
@@ -89,7 +90,6 @@ impl ChatMessage {
     }
 
     pub(super) fn refresh_markdown(&mut self) {
-        if !self.user && !self.tool {
         let visible = crate::agent::visible_content(&self.content);
         let visible = crate::a2ui::transcript_fallback(visible);
         let content = if self.reasoning.is_some() {
@@ -97,6 +97,10 @@ impl ChatMessage {
         } else {
             &visible
         };
+        if self.transcript.text() != content {
+            self.transcript = text_editor::Content::with_text(content);
+        }
+        if !self.user && !self.tool {
             self.markdown = markdown::Content::parse(content);
         }
     }
@@ -165,6 +169,7 @@ impl From<StoredMessage> for ChatMessage {
             reasoning_open: false,
             content: message.content,
             markdown: iced::widget::markdown::Content::new(),
+            transcript: iced::widget::text_editor::Content::new(),
             a2ui_lines_processed: 0,
             a2ui_errors: Vec::new(),
             a2ui_replies: Vec::new(),
@@ -341,6 +346,7 @@ impl App {
             return;
         }
         self.a2ui_auto_switch_pending = true;
+        self.context_notice = None;
         #[cfg(target_os = "macos")]
         self.tool_cards.clear();
         #[cfg(target_os = "macos")]
@@ -633,6 +639,9 @@ impl App {
             match active.events.try_recv() {
                 Ok(GenerationEvent::Loading) => {}
                 Ok(GenerationEvent::Activity(activity)) => {
+                    if activity.starts_with("Rebuilding context:") {
+                        self.context_notice = Some(activity.to_owned());
+                    }
                     self.activity = Some(activity.into());
                 }
                 Ok(GenerationEvent::Compacted(_)) => {
@@ -1666,6 +1675,7 @@ mod tests {
             reasoning_open: false,
             content: content.to_owned(),
             markdown: iced::widget::markdown::Content::new(),
+            transcript: iced::widget::text_editor::Content::new(),
             a2ui_lines_processed: 0,
             a2ui_errors: Vec::new(),
             a2ui_replies: Vec::new(),
@@ -1727,6 +1737,7 @@ mod tests {
             content: "### Core / Setup\n\n| File | Lines |\n|---|---:|\n| `src/app.rs` | **1,750** |\n| `src/engine.rs` | 2,400 |\n\n### Summary\n\nDone."
                 .to_owned(),
             markdown: iced::widget::markdown::Content::new(),
+            transcript: iced::widget::text_editor::Content::new(),
             a2ui_lines_processed: 0,
             a2ui_errors: Vec::new(),
             a2ui_replies: Vec::new(),
@@ -1792,6 +1803,7 @@ mod tests {
             reasoning_open: false,
             content: format!("message {id}"),
             markdown: iced::widget::markdown::Content::new(),
+            transcript: iced::widget::text_editor::Content::new(),
             a2ui_lines_processed: 0,
             a2ui_errors: Vec::new(),
             a2ui_replies: Vec::new(),
@@ -1829,6 +1841,7 @@ mod tests {
                 reasoning_open: false,
                 content: format!("message {id}"),
                 markdown: iced::widget::markdown::Content::new(),
+                transcript: iced::widget::text_editor::Content::new(),
                 a2ui_lines_processed: 0,
                 a2ui_errors: Vec::new(),
                 a2ui_replies: Vec::new(),

src/app/projects.rs

@@ -175,6 +175,7 @@ impl App {
         self.remember_project(project_id);
         self.selected_session = None;
         self.conversation.clear();
+        self.context_notice = None;
         self.clear_a2ui();
         self.composer.clear();
         self.queued_inputs.clear();
@@ -188,6 +189,7 @@ impl App {
     pub(super) fn discard_session(&mut self, project_id: i32) {
         if self.drafts.remove(&project_id).is_some() && self.draft_selected(project_id) {
             self.conversation.clear();
+            self.context_notice = None;
             self.clear_a2ui();
             self.composer.clear();
             self.queued_inputs.clear();

src/app/view.rs

@@ -53,16 +53,46 @@ const TRAFFIC_LIGHT_WIDTH: f32 = 78.0;
 
 impl App {
     pub(crate) fn view(&self, id: window::Id) -> Element<'_, Message> {
-        if self.model_manager_window == Some(id) {
+        let content = if self.model_manager_window == Some(id) {
             self.model_manager()
+        } else if self.help_window == Some(id) {
+            self.help_view()
         } else {
-            let content = self.main_view();
+            self.main_view()
+        };
         #[cfg(target_os = "macos")]
-            return crate::native_edit::native_edit(content, self.native_edit_commands.clone())
+        return crate::native_edit::native_edit(
+            content,
+            self.native_edit_commands.clone(),
+            self.native_edit_availability.clone(),
+        )
         .into();
         #[cfg(not(target_os = "macos"))]
         content
     }
+
+    fn help_view(&self) -> Element<'_, Message> {
+        container(
+            scrollable(
+                container(
+                    markdown::view(
+                        self.help_markdown.items(),
+                        markdown::Settings::with_text_size(
+                            15,
+                            markdown::Style::from_palette(app_theme().palette()),
+                        ),
+                    )
+                    .map(Message::OpenLink),
+                )
+                .max_width(760)
+                .padding(32),
+            )
+            .height(Length::Fill),
+        )
+        .center_x(Length::Fill)
+        .height(Length::Fill)
+        .style(sidebar_style)
+        .into()
     }
 
     /// Whether a dialog covers the window. Focus moves through the whole widget

src/app/view/chat.rs

@@ -55,7 +55,6 @@ impl App {
                     .spacing(8),
                 );
             } else {
-                let markdown_style = markdown::Style::from_palette(app_theme().palette());
                 for (index, message) in self.conversation.iter().enumerate() {
                     if message.compaction {
                         messages = messages.push(
@@ -124,22 +123,17 @@ impl App {
                         }
                     }
                     if !message.content.is_empty() {
-                        if message.user || message.tool || message.markdown.items().is_empty() {
-                            let content = if message.reasoning.is_some() {
-                                crate::agent::visible_content(&message.content).trim_start()
-                            } else {
-                                crate::agent::visible_content(&message.content)
-                            };
-                            body = body.push(text(content).size(14));
-                        } else {
                         body = body.push(
-                                markdown::view(
+                            text_editor(&message.transcript)
-                                    message.markdown.items(),
+                                .id(iced::widget::Id::from(format!(
-                                    markdown::Settings::with_text_size(14, markdown_style),
+                                    "transcript-{}-{index}",
-                                )
+                                    message.id
-                                .map(Message::OpenLink),
+                                )))
+                                .on_action(move |action| Message::TranscriptAction(index, action))
+                                .padding(0)
+                                .size(14)
+                                .style(selectable_text_style),
                         );
-                        }
                     } else if active && message.reasoning.is_none() {
                         body = body.push(
                             text(self.activity.as_deref().unwrap_or("Loading model…")).size(14),
@@ -292,6 +286,20 @@ impl App {
                     .spacing(6)
                     .align_y(Alignment::Center),
                 );
+            if let Some(notice) = &self.context_notice {
+                messages = messages.push(
+                    container(
+                        column![
+                            text("Context rebuild").size(11),
+                            text(notice).size(13).color(muted_text()),
+                        ]
+                        .spacing(5),
+                    )
+                    .padding(14)
+                    .width(Length::Fill)
+                    .style(preference_group_style),
+                );
+            }
             let transcript = scrollable(messages)
                 .id(chat_scroll_id())
                 .height(Length::Fill);
@@ -337,6 +345,19 @@ impl App {
     }
 }
 
+fn selectable_text_style(
+    theme: &Theme,
+    _status: iced::widget::text_editor::Status,
+) -> iced::widget::text_editor::Style {
+    iced::widget::text_editor::Style {
+        background: Background::Color(Color::TRANSPARENT),
+        border: Border::default(),
+        placeholder: muted_text(),
+        value: theme.palette().text,
+        selection: theme.extended_palette().primary.weak.color,
+    }
+}
+
 fn generation_summary(stats: crate::app::generation::GenerationStats) -> Element<'static, Message> {
     column![
         row![

src/engine.rs

@@ -467,6 +467,19 @@ pub(crate) struct GenerationOutput {
     pub(crate) checkpoint_bytes: u64,
 }
 
+struct CheckpointSelection {
+    found: bool,
+    incompatible: bool,
+}
+
+fn checkpoint_rebuild_activity(incompatible: bool) -> &'static str {
+    if incompatible {
+        "Rebuilding context: the checkpoint belongs to a different model or model configuration."
+    } else {
+        "Rebuilding context: the saved history or generation settings changed."
+    }
+}
+
 #[cfg(target_os = "macos")]
 pub(crate) struct CompactionOutput {
     pub(crate) summary: String,
@@ -543,6 +556,7 @@ impl Generator {
         self.executor.model().summary()
     }
 
+    #[allow(clippy::too_many_arguments)]
     pub(crate) fn generate(
         &mut self,
         checkpoint: &Path,
@@ -551,14 +565,19 @@ impl Generator {
         cancelled: &AtomicBool,
         mut emit: impl FnMut(bool, String),
         mut progress: impl FnMut(u32, u32, Option<f32>),
+        mut phase: impl FnMut(&'static str),
     ) -> Result<GenerationOutput, String> {
         let history = messages
             .split_last()
             .map_or(messages, |(_, history)| history);
-        self.select_checkpoint(
+        let checkpoint_present = checkpoint.is_file();
+        let selected = self.select_checkpoint(
             checkpoint,
             conversation_tag(&settings.system_prompt, settings.reasoning_mode, history),
         )?;
+        if checkpoint_present && !selected.found {
+            phase(checkpoint_rebuild_activity(selected.incompatible));
+        }
         let result = self.generate_inner(messages, settings, cancelled, &mut emit, &mut progress);
         self.publish_execution_stats();
         let (mut output, prompt_complete) = result?;
@@ -632,7 +651,7 @@ impl Generator {
         let mut previous_checkpoint = self.checkpoint.clone();
         if self.executor.checkpoint_tag() != history_tag {
             if let Some(entry) = store.find(&history_key, self.executor.context()) {
-                if self.select_checkpoint(&entry.checkpoint, entry.tag)? {
+                if self.select_checkpoint(&entry.checkpoint, entry.tag)?.found {
                     store.touch(&entry)?;
                     self.last_store_tokens = entry.tokens;
                     previous_checkpoint = Some(entry.checkpoint);
@@ -861,19 +880,25 @@ impl Generator {
         &mut self,
         checkpoint: &Path,
         expected_tag: [u8; 32],
-    ) -> Result<bool, String> {
+    ) -> Result<CheckpointSelection, String> {
         let resident_hit = self.activate_resident(checkpoint.to_owned())?;
         if resident_hit && self.executor.checkpoint_tag() == expected_tag {
             self.checkpoint = Some(checkpoint.to_owned());
             self.metrics.kv_lookup(KvLookup::MemoryHit);
-            return Ok(true);
+            return Ok(CheckpointSelection {
+                found: true,
+                incompatible: false,
+            });
         }
         if self.checkpoint.as_deref() == Some(checkpoint) {
             if !checkpoint.is_file() {
                 self.executor.reset()?;
                 self.checkpoint = None;
                 self.metrics.kv_lookup(KvLookup::Miss);
-                return Ok(false);
+                return Ok(CheckpointSelection {
+                    found: false,
+                    incompatible: false,
+                });
             }
             let found = self.executor.checkpoint_tag() == expected_tag;
             self.metrics.kv_lookup(if found {
@@ -881,7 +906,10 @@ impl Generator {
             } else {
                 KvLookup::Miss
             });
-            return Ok(found);
+            return Ok(CheckpointSelection {
+                found,
+                incompatible: false,
+            });
         }
         self.executor.reset()?;
         self.metrics.kv_read_started();
@@ -892,6 +920,7 @@ impl Generator {
         self.metrics
             .kv_read_finished(started.elapsed(), loaded.is_err());
         let found = matches!(loaded, Ok(true)) && self.executor.checkpoint_tag() == expected_tag;
+        let incompatible = loaded.is_err();
         let lookup = match loaded {
             Ok(true) if found => KvLookup::DiskHit,
             Ok(true) | Ok(false) => KvLookup::Miss,
@@ -903,7 +932,10 @@ impl Generator {
         };
         self.metrics.kv_lookup(lookup);
         self.checkpoint = Some(checkpoint.to_owned());
-        Ok(found)
+        Ok(CheckpointSelection {
+            found,
+            incompatible,
+        })
     }
 
     fn activate_resident(&mut self, key: PathBuf) -> Result<bool, String> {
@@ -1616,6 +1648,12 @@ mod sampling_tests {
         assert!(conversation_key("System", ReasoningMode::High, &messages).starts_with(&prefix));
     }
 
+    #[test]
+    fn checkpoint_rebuilds_explain_compatibility_and_history_misses() {
+        assert!(checkpoint_rebuild_activity(true).contains("different model"));
+        assert!(checkpoint_rebuild_activity(false).contains("history"));
+    }
+
     #[test]
     #[ignore = "requires the 80 GiB Flash checkpoint and Apple Metal"]
     fn metal_executes_real_flash_token() {

src/native_edit.rs

@@ -1,4 +1,4 @@
-use std::collections::VecDeque;
+use std::collections::{HashMap, VecDeque};
 use std::sync::{Arc, Mutex};
 
 use iced::advanced::layout;
@@ -22,10 +22,26 @@ pub(crate) enum EditCommand {
 
 pub(crate) type EditCommandQueue = Arc<Mutex<VecDeque<EditCommand>>>;
 
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub(crate) struct EditAvailability {
+    pub(crate) undo: bool,
+    pub(crate) redo: bool,
+    pub(crate) cut: bool,
+    pub(crate) copy: bool,
+    pub(crate) paste: bool,
+    pub(crate) select_all: bool,
+}
+
+pub(crate) type EditAvailabilityState = Arc<Mutex<EditAvailability>>;
+
 pub(crate) fn command_queue() -> EditCommandQueue {
     Arc::new(Mutex::new(VecDeque::new()))
 }
 
+pub(crate) fn availability_state() -> EditAvailabilityState {
+    Arc::new(Mutex::new(EditAvailability::default()))
+}
+
 pub(crate) fn queue_command(queue: &EditCommandQueue, command: EditCommand) {
     queue
         .lock()
@@ -44,22 +60,131 @@ fn pop_command(queue: &EditCommandQueue) -> Option<EditCommand> {
 pub(crate) struct NativeEdit<'a, Message, Theme = iced::Theme, Renderer = iced::Renderer> {
     content: Element<'a, Message, Theme, Renderer>,
     commands: EditCommandQueue,
+    availability: EditAvailabilityState,
 }
 
 impl<'a, Message, Theme, Renderer> NativeEdit<'a, Message, Theme, Renderer> {
     fn new(
         content: impl Into<Element<'a, Message, Theme, Renderer>>,
         commands: EditCommandQueue,
+        availability: EditAvailabilityState,
     ) -> Self {
         Self {
             content: content.into(),
             commands,
+            availability,
         }
     }
 }
 
+#[derive(Clone, Debug, Hash, PartialEq, Eq)]
+enum ControlId {
+    Named(iced::widget::Id),
+    Position(usize),
+}
+
+#[derive(Debug)]
+struct History {
+    values: Vec<String>,
+    current: usize,
+}
+
 #[derive(Default)]
-struct State;
+struct State {
+    histories: HashMap<ControlId, History>,
+    active: Option<ControlId>,
+    window_focused: bool,
+}
+
+#[derive(Default)]
+struct FocusedControl {
+    current: usize,
+    pending_text: Option<String>,
+    focused: Option<(ControlId, Option<String>)>,
+}
+
+impl<T> Operation<T> for FocusedControl {
+    fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation<T>)) {
+        operate(self);
+    }
+
+    fn text_input(
+        &mut self,
+        _id: Option<&iced::widget::Id>,
+        _bounds: Rectangle,
+        state: &mut dyn iced::advanced::widget::operation::TextInput,
+    ) {
+        self.pending_text = Some(state.text().to_owned());
+    }
+
+    fn focusable(
+        &mut self,
+        id: Option<&iced::widget::Id>,
+        _bounds: Rectangle,
+        state: &mut dyn iced::advanced::widget::operation::Focusable,
+    ) {
+        if state.is_focused() {
+            self.focused = Some((
+                id.cloned()
+                    .map_or(ControlId::Position(self.current), ControlId::Named),
+                self.pending_text.take(),
+            ));
+        } else {
+            self.pending_text = None;
+        }
+        self.current += 1;
+    }
+}
+
+impl State {
+    fn observe(&mut self, focused: Option<&(ControlId, Option<String>)>) {
+        self.active = focused.map(|(control, _)| control.clone());
+        let Some((control, Some(value))) = focused else {
+            return;
+        };
+        let history = self
+            .histories
+            .entry(control.clone())
+            .or_insert_with(|| History {
+                values: vec![value.clone()],
+                current: 0,
+            });
+        if history.values[history.current] != *value {
+            history.values.truncate(history.current + 1);
+            history.values.push(value.clone());
+            history.current += 1;
+        }
+    }
+
+    fn replacement(&mut self, command: EditCommand) -> Option<String> {
+        let history = self.histories.get_mut(self.active.as_ref()?)?;
+        match command {
+            EditCommand::Undo if history.current > 0 => history.current -= 1,
+            EditCommand::Redo if history.current + 1 < history.values.len() => {
+                history.current += 1;
+            }
+            _ => return None,
+        }
+        Some(history.values[history.current].clone())
+    }
+
+    fn availability(&self, focused: Option<&(ControlId, Option<String>)>) -> EditAvailability {
+        let Some((control, text)) = focused else {
+            return EditAvailability::default();
+        };
+        let editable = text.is_some();
+        let history = self.histories.get(control);
+        EditAvailability {
+            undo: editable && history.is_some_and(|history| history.current > 0),
+            redo: editable
+                && history.is_some_and(|history| history.current + 1 < history.values.len()),
+            cut: editable,
+            copy: true,
+            paste: editable,
+            select_all: true,
+        }
+    }
+}
 
 fn modifier_sync_event(event: &Event) -> Option<Event> {
     let Event::Keyboard(keyboard::Event::KeyPressed { modifiers, .. }) = event else {
@@ -117,7 +242,7 @@ where
     }
 
     fn state(&self) -> tree::State {
-        tree::State::new(State)
+        tree::State::new(State::default())
     }
 
     fn children(&self) -> Vec<Tree> {
@@ -166,11 +291,44 @@ where
         shell: &mut Shell<'_, Message>,
         viewport: &Rectangle,
     ) {
-        if matches!(
+        let state = tree.state.downcast_mut::<State>();
+        match event {
+            Event::Window(iced::window::Event::Focused) => state.window_focused = true,
+            Event::Window(iced::window::Event::Unfocused) => state.window_focused = false,
+            _ => {}
+        }
+        if state.window_focused
+            && matches!(
                 event,
                 Event::Window(iced::window::Event::RedrawRequested(_))
-        ) {
+            )
+        {
             while let Some(command) = pop_command(&self.commands) {
+                if let Some(replacement) = state.replacement(command) {
+                    let previous = clipboard.read(iced::advanced::clipboard::Kind::Standard);
+                    clipboard.write(iced::advanced::clipboard::Kind::Standard, replacement);
+                    for command in [EditCommand::SelectAll, EditCommand::Paste] {
+                        for command_event in command_events(command) {
+                            self.content.as_widget_mut().update(
+                                &mut tree.children[0],
+                                &command_event,
+                                layout,
+                                cursor,
+                                renderer,
+                                clipboard,
+                                shell,
+                                viewport,
+                            );
+                        }
+                    }
+                    if let Some(previous) = previous {
+                        clipboard.write(iced::advanced::clipboard::Kind::Standard, previous);
+                    }
+                    continue;
+                }
+                if matches!(command, EditCommand::Undo | EditCommand::Redo) {
+                    continue;
+                }
                 for command_event in command_events(command) {
                     self.content.as_widget_mut().update(
                         &mut tree.children[0],
@@ -209,6 +367,19 @@ where
             shell,
             viewport,
         );
+
+        let mut focused = FocusedControl::default();
+        self.content
+            .as_widget_mut()
+            .operate(&mut tree.children[0], layout, renderer, &mut focused);
+        if state.window_focused {
+            state.observe(focused.focused.as_ref());
+            *self
+                .availability
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner()) =
+                state.availability(focused.focused.as_ref());
+        }
     }
 
     fn mouse_interaction(
@@ -282,8 +453,9 @@ where
 pub(crate) fn native_edit<'a, Message, Theme, Renderer>(
     content: impl Into<Element<'a, Message, Theme, Renderer>>,
     commands: EditCommandQueue,
+    availability: EditAvailabilityState,
 ) -> NativeEdit<'a, Message, Theme, Renderer> {
-    NativeEdit::new(content, commands)
+    NativeEdit::new(content, commands, availability)
 }
 
 #[cfg(test)]
@@ -310,4 +482,14 @@ mod tests {
             Event::Keyboard(keyboard::Event::ModifiersChanged(modifiers)) if modifiers.is_empty()
         ));
     }
+
+    #[test]
+    fn edit_history_supports_undo_and_redo() {
+        let control = ControlId::Position(0);
+        let mut state = State::default();
+        state.observe(Some(&(control.clone(), Some("a".into()))));
+        state.observe(Some(&(control.clone(), Some("ab".into()))));
+        assert_eq!(state.replacement(EditCommand::Undo).as_deref(), Some("a"));
+        assert_eq!(state.replacement(EditCommand::Redo).as_deref(), Some("ab"));
+    }
 }

src/native_menu.rs

@@ -1,10 +1,14 @@
 use muda::accelerator::{Accelerator, CMD_OR_CTRL, Code, Modifiers};
-use muda::{Menu, MenuEvent, MenuItem, PredefinedMenuItem, Submenu};
+use muda::{CheckMenuItem, Menu, MenuEvent, MenuItem, PredefinedMenuItem, Submenu};
 
 use crate::native_edit::EditCommand;
 
 const PREFERENCES: &str = "preferences";
 const MODEL_MANAGER: &str = "model-manager";
+const NEW_CHAT: &str = "new-chat";
+const EXPORT_CHAT: &str = "export-chat";
+const TOGGLE_SIDEBAR: &str = "toggle-sidebar";
+const HELP: &str = "help";
 const UNDO: &str = "undo";
 const REDO: &str = "redo";
 const CUT: &str = "cut";
@@ -14,20 +18,36 @@ const SELECT_ALL: &str = "select-all";
 
 pub(crate) struct NativeMenu {
     _menu: Menu,
+    new_chat: MenuItem,
+    export_chat: MenuItem,
+    sidebar: CheckMenuItem,
+    undo: MenuItem,
+    redo: MenuItem,
+    cut: MenuItem,
+    copy: MenuItem,
+    paste: MenuItem,
+    select_all: MenuItem,
 }
 
 #[derive(Clone, Copy, Debug)]
 pub(crate) enum NativeMenuEvent {
     Preferences,
     ModelManager,
+    NewChat,
+    ExportChat,
+    ToggleSidebar,
+    Help,
     Edit(EditCommand),
 }
 
 pub(crate) fn install() -> Result<NativeMenu, String> {
     let menu = Menu::new();
     let application = Submenu::new("DS4Server", true);
+    let file = Submenu::new("File", true);
     let edit = Submenu::new("Edit", true);
+    let view = Submenu::new("View", true);
     let window = Submenu::new("Window", true);
+    let help = Submenu::new("Help", true);
     let preferences = MenuItem::with_id(
         PREFERENCES,
         "Preferences…",
@@ -43,6 +63,37 @@ pub(crate) fn install() -> Result<NativeMenu, String> {
             Code::KeyM,
         )),
     );
+    let new_chat = MenuItem::with_id(
+        NEW_CHAT,
+        "New Chat",
+        false,
+        Some(Accelerator::new(Some(Modifiers::SUPER), Code::KeyN)),
+    );
+    let export_chat = MenuItem::with_id(
+        EXPORT_CHAT,
+        "Export Chat as Markdown…",
+        false,
+        Some(Accelerator::new(
+            Some(Modifiers::SUPER | Modifiers::SHIFT),
+            Code::KeyS,
+        )),
+    );
+    let sidebar = CheckMenuItem::with_id(
+        TOGGLE_SIDEBAR,
+        "Show Sidebar",
+        true,
+        true,
+        Some(Accelerator::new(Some(Modifiers::SUPER), Code::KeyB)),
+    );
+    let open_help = MenuItem::with_id(
+        HELP,
+        "DS4Server Help",
+        true,
+        Some(Accelerator::new(
+            Some(Modifiers::SUPER | Modifiers::SHIFT),
+            Code::Slash,
+        )),
+    );
     let undo = edit_item(UNDO, "Undo", Code::KeyZ, None);
     let redo = edit_item(REDO, "Redo", Code::KeyZ, Some(Modifiers::SHIFT));
     let cut = edit_item(CUT, "Cut", Code::KeyX, None);
@@ -65,6 +116,13 @@ pub(crate) fn install() -> Result<NativeMenu, String> {
             &PredefinedMenuItem::quit(None),
         ])
         .map_err(|error| error.to_string())?;
+    file.append_items(&[
+        &new_chat,
+        &export_chat,
+        &PredefinedMenuItem::separator(),
+        &PredefinedMenuItem::close_window(None),
+    ])
+    .map_err(|error| error.to_string())?;
     edit.append_items(&[
         &undo,
         &redo,
@@ -75,21 +133,53 @@ pub(crate) fn install() -> Result<NativeMenu, String> {
         &select_all,
     ])
     .map_err(|error| error.to_string())?;
+    view.append_items(&[&sidebar, &PredefinedMenuItem::separator(), &model_manager])
+        .map_err(|error| error.to_string())?;
     window
         .append_items(&[
-            &model_manager,
-            &PredefinedMenuItem::separator(),
             &PredefinedMenuItem::minimize(None),
             &PredefinedMenuItem::maximize(None),
             &PredefinedMenuItem::close_window(None),
             &PredefinedMenuItem::bring_all_to_front(None),
         ])
         .map_err(|error| error.to_string())?;
-    menu.append_items(&[&application, &edit, &window])
+    help.append(&open_help).map_err(|error| error.to_string())?;
+    menu.append_items(&[&application, &file, &edit, &view, &window, &help])
         .map_err(|error| error.to_string())?;
     menu.init_for_nsapp();
     window.set_as_windows_menu_for_nsapp();
-    Ok(NativeMenu { _menu: menu })
+    Ok(NativeMenu {
+        _menu: menu,
+        new_chat,
+        export_chat,
+        sidebar,
+        undo,
+        redo,
+        cut,
+        copy,
+        paste,
+        select_all,
+    })
+}
+
+impl NativeMenu {
+    pub(crate) fn update(
+        &self,
+        project_active: bool,
+        chat_active: bool,
+        sidebar_visible: bool,
+        edit: crate::native_edit::EditAvailability,
+    ) {
+        self.new_chat.set_enabled(project_active);
+        self.export_chat.set_enabled(chat_active);
+        self.sidebar.set_checked(sidebar_visible);
+        self.undo.set_enabled(edit.undo);
+        self.redo.set_enabled(edit.redo);
+        self.cut.set_enabled(edit.cut);
+        self.copy.set_enabled(edit.copy);
+        self.paste.set_enabled(edit.paste);
+        self.select_all.set_enabled(edit.select_all);
+    }
 }
 
 pub(crate) fn next_event() -> Option<NativeMenuEvent> {
@@ -97,6 +187,10 @@ pub(crate) fn next_event() -> Option<NativeMenuEvent> {
         let event = match event.id.0.as_str() {
             PREFERENCES => NativeMenuEvent::Preferences,
             MODEL_MANAGER => NativeMenuEvent::ModelManager,
+            NEW_CHAT => NativeMenuEvent::NewChat,
+            EXPORT_CHAT => NativeMenuEvent::ExportChat,
+            TOGGLE_SIDEBAR => NativeMenuEvent::ToggleSidebar,
+            HELP => NativeMenuEvent::Help,
             UNDO => NativeMenuEvent::Edit(EditCommand::Undo),
             REDO => NativeMenuEvent::Edit(EditCommand::Redo),
             CUT => NativeMenuEvent::Edit(EditCommand::Cut),

src/runtime.rs

@@ -374,6 +374,9 @@ fn run_command(
                 &command.cancel,
                 &mut emit,
                 &mut progress,
+                |activity| {
+                    let _ = command.events.send(GenerationEvent::Activity(activity));
+                },
             ),
             CheckpointTarget::Transient(directory) | CheckpointTarget::OneShot(directory) => {
                 generator.generate_transient(