Merge develop into main (#327)

## New features
- Implemented support for app packaging in firmware and `tactility.py`: load `.app` files instead of `.elf` files. Install apps remotely or via `FileBrowser`.
- Ensure headless mode works: all services that require LVGL can deal with the absence of a display
- Service `onStart()` is now allowed to fail (return `bool` result)
- Added and improved various file-related helper functions

## Improvements
- Completely revamped the SystemInfo app UI
- Improved Calculator UI of internal and external variant
- Fix Chat UI and removed the emoji buttons for now
- Fix for toolbar bottom padding issue in all apps

## Fixes
- Fix for allowing recursive locking for certain SPI SD cards
& more

TactilityCore/Include/Tactility/file/File.h

@@ -67,7 +67,11 @@ bool writeString(const std::string& filepath, const std::string& content);
  * @param[in] mode the mode to use when creating directories
  * @return true when the specified path was found, or otherwise creates the directories recursively with the specified mode.
  */
-bool findOrCreateDirectory(std::string path, mode_t mode);
+bool findOrCreateDirectory(const std::string& path, mode_t mode);
+
+bool findOrCreateParentDirectory(const std::string& path, mode_t mode);
+
+bool deleteRecursively(const std::string& path);
 
 /**
  * Concatenate a child path with a parent path, ensuring proper slash inbetween
@@ -77,6 +81,8 @@ bool findOrCreateDirectory(std::string path, mode_t mode);
  */
 std::string getChildPath(const std::string& basePath, const std::string& childPath);
 
+std::string getLastPathSegment(const std::string& path);
+
 typedef int (*ScandirFilter)(const dirent*);
 
 typedef bool (*ScandirSort)(const dirent&, const dirent&);
@@ -91,6 +97,21 @@ bool isFile(const std::string& path);
 
 bool isDirectory(const std::string& path);
 
+/**
+ * A scandir()-like implementation that works on ESP32.
+ * It does not return "." and ".." items but otherwise functions the same.
+ * It returns an allocated output array with allocated dirent instances.
+ * The caller is responsible for free-ing the memory of these.
+ *
+ * @param[in] path path the scan for files and directories
+ * @param[out] onEntry a pointer to a function that accepts an entry
+ * @return true if the directory exists and listing its contents was successful
+ */
+bool listDirectory(
+    const std::string& path,
+    std::function<void(const dirent&)> onEntry
+);
+
 /**
  * A scandir()-like implementation that works on ESP32.
  * It does not return "." and ".." items but otherwise functions the same.
@@ -106,8 +127,8 @@ bool isDirectory(const std::string& path);
 int scandir(
     const std::string& path,
     std::vector<dirent>& outList,
-    ScandirFilter _Nullable filter,
-    ScandirSort _Nullable sort
+    ScandirFilter _Nullable filter = nullptr,
+    ScandirSort _Nullable sort = nullptr
 );
 
 bool readLines(const std::string& filePath, bool stripNewLine, std::function<void(const char* line)> callback);