Fix import issues and f-string syntax

- Fix f-string formatting in engine.py timestamp function
- Add fallback import system in CLI for both package and module usage
- Ensure compatibility when running as installed package or as module

Author: maxitoon

src/transcriber/cli.py

@@ -7,8 +7,14 @@
 
 import click
 
-from .engine import TranscriptionEngine
-from .downloader import YouTubeDownloader
+try:
+    # Try absolute imports first (when installed as package)
+    from transcriber.engine import TranscriptionEngine
+    from transcriber.downloader import YouTubeDownloader
+except ImportError:
+    # Fall back to relative imports (when running as module)
+    from .engine import TranscriptionEngine
+    from .downloader import YouTubeDownloader
 
 
 @click.group()

src/transcriber/engine.py

@@ -145,9 +145,9 @@ def _format_timestamp(self, seconds: float, vtt: bool = False) -> str:
         seconds = seconds % 60
 
         if vtt:
-            return f"{hours"02d"}:{minutes"02d"}:{seconds"06.3f"}".replace(".", ",")
+            return f"{hours:02d}:{minutes:02d}:{seconds:06.3f}".replace(".", ",")
         else:
-            return f"{hours"02d"}:{minutes"02d"}:{seconds"06.3f"}"
+            return f"{hours:02d}:{minutes:02d}:{seconds:06.3f}"
 
     def _clean_result_for_json(self, result: Dict[str, Any]) -> Dict[str, Any]:
         """Remove non-serializable data from result."""