Make inline completion helper opt-in by default

editor/src/BufferOps.h

@@ -305,6 +305,7 @@ inline void EditorState::applySession(const SessionData& session) {
 
 inline void EditorState::applySettingsToState() {
     ui.showMinimap = settings.getShowMinimap();
+    ui.showCompletionHelper = settings.getShowCompletionHelper();
     ui.showLineNumbers = settings.getShowLineNumbers();
     ui.layoutPreset = LayoutManager::presetFromName(settings.getLayoutPreset());
     keys.setProfile(KeybindingManager::profileFromName(settings.getKeybindingProfile()));
@@ -320,6 +321,7 @@ inline void EditorState::loadSettingsFromDisk() {
 
 inline void EditorState::saveSettingsToDisk() {
     settings.setShowMinimap(ui.showMinimap);
+    settings.setShowCompletionHelper(ui.showCompletionHelper);
     settings.setShowLineNumbers(ui.showLineNumbers);
     settings.setLayoutPreset(LayoutManager::presetName(ui.layoutPreset));
     settings.setKeybindingProfile(KeybindingManager::profileName(keys.getProfile()));

editor/src/SettingsManager.h

@@ -54,6 +54,8 @@ public:
     void setAutoSaveSeconds(int seconds) { autoSaveSeconds_ = seconds; }
     bool getShowMinimap() const { return showMinimap_; }
     void setShowMinimap(bool value) { showMinimap_ = value; }
+    bool getShowCompletionHelper() const { return showCompletionHelper_; }
+    void setShowCompletionHelper(bool value) { showCompletionHelper_ = value; }
     bool getShowLineNumbers() const { return showLineNumbers_; }
     void setShowLineNumbers(bool value) { showLineNumbers_ = value; }
     bool getReduceMotion() const { return reduceMotion_; }
@@ -101,6 +103,7 @@ public:
             updateUrl_ = j.value("updateUrl", updateUrl_);
             autoSaveSeconds_ = j.value("autoSaveSeconds", autoSaveSeconds_);
             showMinimap_ = j.value("showMinimap", showMinimap_);
+            showCompletionHelper_ = j.value("showCompletionHelper", showCompletionHelper_);
             showLineNumbers_ = j.value("showLineNumbers", showLineNumbers_);
             reduceMotion_ = j.value("reduceMotion", reduceMotion_);
             useAnnotationShapes_ = j.value("useAnnotationShapes", useAnnotationShapes_);
@@ -149,6 +152,7 @@ public:
             j["updateUrl"] = updateUrl_;
             j["autoSaveSeconds"] = autoSaveSeconds_;
             j["showMinimap"] = showMinimap_;
+            j["showCompletionHelper"] = showCompletionHelper_;
             j["showLineNumbers"] = showLineNumbers_;
             j["reduceMotion"] = reduceMotion_;
             j["useAnnotationShapes"] = useAnnotationShapes_;
@@ -234,6 +238,7 @@ private:
     std::string updateUrl_ = "https://example.com/whetstone/releases.json";
     int autoSaveSeconds_ = 0;
     bool showMinimap_ = false;
+    bool showCompletionHelper_ = false;
     bool showLineNumbers_ = true;
     bool reduceMotion_ = false;
     bool useAnnotationShapes_ = true;

editor/src/panels/EditorPanel.h

@@ -321,12 +321,19 @@ static void renderEditorPanel(EditorState& state) {
                             }
                             if (res.changed) {
                                 state.onTextChanged();
-                                state.completionPending = true;
-                                state.completionLastChange = ImGui::GetTime();
-                                state.completionVisible = false;
-                                state.completionDismissed = false;
-                                state.completionSelected = 0;
-                                if (state.lsp) state.lsp->clearCompletionItems();
+                                if (state.ui.showCompletionHelper) {
+                                    state.completionPending = true;
+                                    state.completionLastChange = ImGui::GetTime();
+                                    state.completionVisible = false;
+                                    state.completionDismissed = false;
+                                    state.completionSelected = 0;
+                                    if (state.lsp) state.lsp->clearCompletionItems();
+                                } else {
+                                    state.completionPending = false;
+                                    state.completionVisible = false;
+                                    state.completionDismissed = false;
+                                    if (state.lsp) state.lsp->clearCompletionItems();
+                                }
                                 if (state.lsp && state.active() && state.active()->path.rfind("(untitled", 0) != 0) {
                                     int cursor = state.active()->widget.getCursor();
                                     if (cursor > 0 && state.active()->editBuf[cursor - 1] == '(') {
@@ -356,7 +363,9 @@ static void renderEditorPanel(EditorState& state) {
                         }
 
                         double now = ImGui::GetTime();
-                        if (state.completionPending && (now - state.completionLastChange) > 0.2) {
+                        if (state.ui.showCompletionHelper &&
+                            state.completionPending &&
+                            (now - state.completionLastChange) > 0.2) {
                             if (state.lsp && state.active() && state.active()->path.rfind("(untitled", 0) != 0) {
                                 int lineZero = std::max(0, state.active()->cursorLine - 1);
                                 int colZero = std::max(0, state.active()->cursorCol - 1);
@@ -403,7 +412,7 @@ static void renderEditorPanel(EditorState& state) {
                             state.analysisPending = false;
                         }
 
-                        if (state.lsp && state.active()) {
+                        if (state.ui.showCompletionHelper && state.lsp && state.active()) {
                             auto items = state.lsp->getCompletionItems();
                             int cursor = state.active()->widget.getCursor();
                             std::string prefix = EditorState::wordPrefixAt(state.active()->editBuf, cursor);
@@ -525,6 +534,11 @@ static void renderEditorPanel(EditorState& state) {
                                 }
                             }
                         }
+                        if (!state.ui.showCompletionHelper) {
+                            state.completionPending = false;
+                            state.completionVisible = false;
+                            state.completionDismissed = false;
+                        }
 
                         if (state.showSuggestionPopup) {
                             if (ImGui::BeginPopupModal("SuggestionPopup", &state.showSuggestionPopup, ImGuiWindowFlags_AlwaysAutoResize)) {

editor/src/panels/MenuBarPanel.h

@@ -90,6 +90,7 @@ static void renderMenuBar(EditorState& state) {
     if (ImGui::BeginMenu("View")) {
         ImGui::MenuItem("Show Whitespace", nullptr, &state.ui.showWhitespace);
         ImGui::MenuItem("Show Minimap", nullptr, &state.ui.showMinimap);
+        ImGui::MenuItem("Inline Completion Helper", nullptr, &state.ui.showCompletionHelper);
         ImGui::MenuItem("Show Annotations", nullptr, &state.ui.showAnnotations);
         ImGui::MenuItem("Show Outline", nullptr, &state.ui.showOutline);
         ImGui::MenuItem("Terminal", state.keys.getBinding("view.toggleTerminal").toString().c_str(),

editor/src/panels/SettingsPanel.h

@@ -339,6 +339,17 @@ static void renderSettingsPanel(EditorState& state) {
         state.ui.showMinimap = showMinimap;
         settingsChanged = true;
     }
+    bool showCompletionHelper = state.ui.showCompletionHelper;
+    if (ImGui::Checkbox("Inline Completion Helper", &showCompletionHelper)) {
+        state.ui.showCompletionHelper = showCompletionHelper;
+        if (!showCompletionHelper) {
+            state.completionPending = false;
+            state.completionVisible = false;
+            state.completionDismissed = false;
+            if (state.lsp) state.lsp->clearCompletionItems();
+        }
+        settingsChanged = true;
+    }
     bool showLineNumbers = state.ui.showLineNumbers;
     if (ImGui::Checkbox("Show Line Numbers", &showLineNumbers)) {
         state.ui.showLineNumbers = showLineNumbers;

editor/src/state/UIFlags.h

@@ -12,6 +12,7 @@ enum class FocusRegion {
 struct UIFlags {
     bool showWhitespace = false;
     bool showMinimap = false;
+    bool showCompletionHelper = false;
     bool showAnnotations = false;
     bool showOutline = true;
     bool showLineNumbers = true;

progress.md

@@ -5318,6 +5318,25 @@ confirming with Enter/Tab).
 - `step54_test` — PASS (10/10) regression coverage
 - `step437_test` — PASS (8/8) regression coverage
 
+### Hotfix E: inline completion helper default-off + toggle
+**Status:** PASS (helper now opt-in)
+
+Changed inline completion helper to default OFF and only appear when explicitly
+enabled by the user.
+
+**Files modified:**
+- `editor/src/state/UIFlags.h` — added `showCompletionHelper` UI flag (default `false`)
+- `editor/src/SettingsManager.h` — added persisted `showCompletionHelper` setting
+- `editor/src/BufferOps.h` — synced `showCompletionHelper` with settings load/save
+- `editor/src/panels/MenuBarPanel.h` — View toggle: `Inline Completion Helper`
+- `editor/src/panels/SettingsPanel.h` — Settings checkbox and cleanup on disable
+- `editor/src/panels/EditorPanel.h` — gated completion requests/rendering behind toggle
+
+**Verification run:**
+- `cmake --build editor/build-native --target whetstone_editor` — PASS
+- `step54_test` — PASS (10/10) regression coverage
+- `step437_test` — PASS (8/8) regression coverage
+
 # Roadmap Planning — Sprints 12-25+
 
 ## Status: Planning Complete (Sprints 12-19 detailed, 20-25 in roadmap.md)