add playFile() blocking method for audio playback (#2048)

summary:
adds a new `playFile(const char *filePath)` method to the `AudioPlayer` class that provides a simple blocking way to play a complete audio file from start to finish.

- new method: `bool playFile(const char *filePath)` in the public section of `AudioPlayer` class
- functionality:
  - sets the audio file path using existing `setPath()` method
  - starts playback with `play()`
  - blocks execution until the entire file finishes playing
  - automatically stops when no more audio data is available
  - returns `true` on success, `false` if file cannot be opened

use case:
i used this library for an ESP32 project at school and needed a blocking method to do nothing BUT play a specific audio file before continuing the program, so i made my own and thought other people might need it!

example usage:
```cpp
AudioPlayer player(source, output, decoder);

...

setup() {
  player.begin();
}

...

loop() {
  // play a complete file (blocking)
  if (player.playFile("/song1.mp3")) {
      // file plays successfully
  } else {
      // file not found or other error occurred
  }

  doSomething();
}
```

this addition shouldn't affect any existing functionality!

Author: JulesCastel

src/AudioTools/CoreAudio/AudioPlayer.h

@@ -252,6 +252,32 @@ class AudioPlayer : public AudioInfoSupport, public VolumeSupport {
     setActive(true);
   }
 
+  /// plays a complete audio file from start to finish (blocking call)
+  /// @param filePath path to the audio file to play
+  /// @return true if file was found and played successfully, false otherwise
+  bool playFile(const char *filePath) {
+    TRACED();
+    if (!setPath(filePath)) {
+      LOGW("Could not open file: %s", filePath);
+      return false;
+    }
+    
+    LOGI("Playing %s", filePath);
+    play();
+    
+    while (isActive()) {
+      size_t bytes_copied = copy();
+      // if no bytes were copied, the file may have ended
+      if (bytes_copied == 0) {
+        stop();
+        break;
+      }
+    }
+    
+    LOGI("%s has finished playing", filePath);
+    return true;
+  }
+
   /// halts the playing: same as setActive(false)
   void stop() {
     TRACED();