Enhance contribution guidelines and improve FloatingGenerateBox component

- Updated CONTRIBUTING.md to include instructions for building with a local Qwen3-TTS development version, facilitating easier testing and development.
- Refactored FloatingGenerateBox component to streamline the rendering of text and instruct fields, improving code readability and maintainability.
- Added functionality to handle auto-resizing of text areas based on content changes, enhancing user experience.
- Improved event handling for keyboard interactions in StoryTrackEditor, allowing for play/pause functionality with the spacebar.
- Introduced a MiniSamplePlayer component in SampleList for better audio playback control, including play, pause, and seek features.
- Implemented sample update functionality in the backend, allowing users to edit reference text for audio samples, with appropriate error handling and user feedback.

backend/transcribe.py

@@ -162,9 +162,10 @@ class WhisperModel:
             # Set language if provided
             forced_decoder_ids = None
             if language:
-                lang_code = "en" if language == "en" else "zh"
+                # Support all languages from frontend: en, zh, ja, ko, de, fr, ru, pt, es, it
+                # Whisper supports these and many more
                 forced_decoder_ids = self.processor.get_decoder_prompt_ids(
-                    language=lang_code,
+                    language=language,
                     task="transcribe",
                 )
             
@@ -221,9 +222,10 @@ class WhisperModel:
             # Set language if provided
             forced_decoder_ids = None
             if language:
-                lang_code = "en" if language == "en" else "zh"
+                # Support all languages from frontend: en, zh, ja, ko, de, fr, ru, pt, es, it
+                # Whisper supports these and many more
                 forced_decoder_ids = self.processor.get_decoder_prompt_ids(
-                    language=lang_code,
+                    language=language,
                     task="transcribe",
                 )