fw/quick_launch: add a Nothing action for inert buttons

src/fw/apps/system/quick_launch_nothing.c

@@ -0,0 +1,26 @@
+/* SPDX-FileCopyrightText: 2026 Core Devices LLC */
+/* SPDX-License-Identifier: Apache-2.0 */
+
+//! The "Nothing" Quick Launch action. Binding a button to it makes the button
+//! inert: the shell recognizes the app id and never launches anything.
+
+#include "quick_launch_nothing.h"
+
+#include "pbl/services/i18n/i18n.h"
+
+static void prv_main(void) {
+  // Never runs; the shell drops the launch before it gets here.
+}
+
+const PebbleProcessMd *quick_launch_nothing_get_app_info(void) {
+  static const PebbleProcessMdSystem s_app_info = {
+    .common = {
+      .main_func = &prv_main,
+      .uuid = QUICK_LAUNCH_NOTHING_UUID,
+      .visibility = ProcessVisibilityQuickLaunch,
+    },
+    /// Quick Launch action that makes the button do nothing at all.
+    .name = i18n_noop("Nothing"),
+  };
+  return &s_app_info.common;
+}

src/fw/apps/system/quick_launch_nothing.h

@@ -0,0 +1,11 @@
+/* SPDX-FileCopyrightText: 2026 Core Devices LLC */
+/* SPDX-License-Identifier: Apache-2.0 */
+
+#pragma once
+
+#include "process_management/app_manager.h"
+
+#define QUICK_LAUNCH_NOTHING_UUID {0xde, 0x6d, 0xa1, 0x7f, 0x1a, 0x10, 0x47, 0x25, \
+                                   0xad, 0xbb, 0x1e, 0xfc, 0x22, 0xe4, 0x3f, 0x04}
+
+const PebbleProcessMd *quick_launch_nothing_get_app_info(void);

src/fw/apps/system/settings/quick_launch.c

@@ -59,8 +59,8 @@ static const char *s_row_titles[NUM_ROWS] = {
 static void prv_get_subtitle_string(AppInstallId app_id, QuickLaunchData *data,
                                     char *buffer, uint8_t buf_len) {
   if (app_id == INSTALL_ID_INVALID) {
-    /// Shown in Quick Launch Settings when the button is disabled.
-    i18n_get_with_buffer("Disabled", buffer, buf_len);
+    /// Shown in Quick Launch Settings when no action or app is bound to the button.
+    i18n_get_with_buffer("Unassigned", buffer, buf_len);
     return;
   } else {
     AppInstallEntry entry;

src/fw/apps/system/settings/quick_launch_app_menu.c

@@ -86,7 +86,8 @@ static void prv_menu_draw_row(OptionMenu *option_menu, GContext* ctx, const Laye
   QuickLaunchAppMenuData *data = context;
   const char *text = NULL;
   if (row == 0) {
-    text = i18n_get("Disable", data);
+    /// Shown in Quick Launch Settings when no action or app is bound to the button.
+    text = i18n_get("Unassigned", data);
   } else {
     AppMenuNode *node = app_menu_data_source_get_node_at_index(&data->data_source,
                                                                row - NUM_CUSTOM_CELLS);

src/fw/shell/normal/system_app_registry_list.json

@@ -673,6 +673,11 @@
       "id": -100,
       "enum": "NOTIFICATIONS_CLEAR_HISTORY",
       "md_fn": "notifications_clear_history_app_get_info"
+    },
+    {
+      "id": -101,
+      "enum": "QUICK_LAUNCH_NOTHING",
+      "md_fn": "quick_launch_nothing_get_app_info"
     }
   ],
   "resource_apps": [

src/fw/shell/normal/watchface.c

@@ -187,6 +187,10 @@ static void prv_launch_timeline_app(AppInstallId app_id, ButtonId button,
 static void prv_launch_quick_launch_app(AppInstallId app_id, ButtonId button,
                                         AppLaunchReason timeline_reason,
                                         AppQuickLaunchAction action) {
+  if (app_id == APP_ID_QUICK_LAUNCH_NOTHING) {
+    return;
+  }
+
   const bool is_timeline = (app_id == APP_ID_TIMELINE) ||
                            (app_id == APP_ID_TIMELINE_PAST) ||
                            (app_id == APP_ID_TIMELINE_FULL);