refactor(cli): centralize Typer app creation and command registration

mini-nav/main.py

@@ -1,16 +1,4 @@
-import typer
-from commands import benchmark, generate, train, visualize
-
-app = typer.Typer(
-    name="mini-nav",
-    help="Mini-Nav: A vision-language navigation system",
-    add_completion=False,
-)
-
-app.command(name="train")(train)
-app.command(name="benchmark")(benchmark)
-app.command(name="visualize")(visualize)
-app.command(name="generate")(generate)
+from commands import app
 
 if __name__ == "__main__":
     app()