feat: add ".." go-up entry to directory picker

The folder picker had no visible way to navigate to a parent directory.
Add a ".." list item (shown when not at root) so users can go up by
selecting it, matching standard file-picker conventions.

Made-with: Cursor

src/activities/util/DirectoryPickerActivity.cpp

@@ -63,6 +63,14 @@ void DirectoryPickerActivity::loadDirectories() {
   StringUtils::sortFileList(directories);
 }
 
+void DirectoryPickerActivity::navigateToParent() {
+  auto slash = basepath.find_last_of('/');
+  basepath = (slash == 0) ? "/" : basepath.substr(0, slash);
+  selectorIndex = 0;
+  loadDirectories();
+  requestUpdate();
+}
+
 void DirectoryPickerActivity::loop() {
   // Absorb the Confirm release from the parent activity that launched us
   if (waitForConfirmRelease) {
@@ -72,14 +80,16 @@ void DirectoryPickerActivity::loop() {
     return;
   }
 
-  // Index 0 = "Save Here", indices 1..N = directory entries
+  const int offset = directoryOffset();
-  const int totalItems = 1 + static_cast<int>(directories.size());
+  const int totalItems = offset + static_cast<int>(directories.size());
 
   if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
     if (selectorIndex == 0) {
       onSelect(basepath);
+    } else if (showGoUp() && selectorIndex == 1) {
+      navigateToParent();
     } else {
-      const auto& dirName = directories[selectorIndex - 1];
+      const auto& dirName = directories[selectorIndex - offset];
       // Strip trailing '/'
       std::string folderName = dirName.substr(0, dirName.length() - 1);
       basepath = (basepath.back() == '/' ? basepath : basepath + "/") + folderName;
@@ -94,11 +104,7 @@ void DirectoryPickerActivity::loop() {
     if (basepath == "/") {
       onCancel();
     } else {
-      auto slash = basepath.find_last_of('/');
+      navigateToParent();
-      basepath = (slash == 0) ? "/" : basepath.substr(0, slash);
-      selectorIndex = 0;
-      loadDirectories();
-      requestUpdate();
     }
     return;
   }
@@ -139,21 +145,24 @@ void DirectoryPickerActivity::render(Activity::RenderLock&&) {
   const int contentTop = metrics.topPadding + metrics.headerHeight + metrics.verticalSpacing;
   const int contentHeight = pageHeight - contentTop - metrics.buttonHintsHeight - metrics.verticalSpacing;
 
-  const int totalItems = 1 + static_cast<int>(directories.size());
+  const int offset = directoryOffset();
+  const int totalItems = offset + static_cast<int>(directories.size());
+  const bool goUp = showGoUp();
 
   GUI.drawList(
       renderer, Rect{0, contentTop, pageWidth, contentHeight}, totalItems, selectorIndex,
-      [this](int index) -> std::string {
+      [this, offset, goUp](int index) -> std::string {
         if (index == 0) {
-          std::string label = std::string(tr(STR_SAVE_HERE)) + " (" + basepath + ")";
+          return std::string(tr(STR_SAVE_HERE)) + " (" + basepath + ")";
-          return label;
         }
-        // Strip trailing '/' for display
+        if (goUp && index == 1) {
-        const auto& dir = directories[index - 1];
+          return "..";
+        }
+        const auto& dir = directories[index - offset];
         return dir.substr(0, dir.length() - 1);
       },
       nullptr,
-      [this](int index) -> UIIcon {
+      [](int index) -> UIIcon {
         return (index == 0) ? UIIcon::File : UIIcon::Folder;
       });
 

src/activities/util/DirectoryPickerActivity.h

@@ -41,4 +41,7 @@ class DirectoryPickerActivity final : public Activity {
   std::function<void()> onCancel;
 
   void loadDirectories();
+  void navigateToParent();
+  [[nodiscard]] bool showGoUp() const { return basepath != "/"; }
+  [[nodiscard]] int directoryOffset() const { return showGoUp() ? 2 : 1; }
 };