Reorganize repository structure for better organization

- Move backend code to swingmusic/ folder
- Move client applications to root level (swingmusic-android, swingmusic-desktop, swingmusic-webclient)
- Remove intermediate backend/ and clients/ folders
- Update README with new folder structure and setup instructions
- Clean and organized repository layout

src/swingmusic/__main__.py

@@ -1,88 +0,0 @@
-import sys
-import pathlib
-import argparse
-import multiprocessing
-
-from swingmusic import settings
-from swingmusic.logger import setup_logger
-from swingmusic import tools as swing_tools
-from swingmusic.settings import AssetHandler, Metadata
-from swingmusic.start_swingmusic import start_swingmusic
-
-parser = argparse.ArgumentParser(
-    prog="swingmusic",
-    description="Awesome Music",
-    formatter_class=argparse.ArgumentDefaultsHelpFormatter,
-)
-
-parser.add_argument(
-    "-v", "--version", action="version", version=f"swingmusic v{Metadata.version}"
-)
-parser.add_argument("--host", default="0.0.0.0", help="Host to run the app on.")
-parser.add_argument(
-    "--port", default=1970, help="HTTP port to run the app on.", type=int
-)
-parser.add_argument(
-    "--debug",
-    default=False,
-    action="store_true",
-    help="If swingmusic should start in debug mode",
-)
-parser.add_argument(
-    "--config",
-    default=settings.Paths.get_default_config_parent_dir(),
-    help="The directory to setup the config folder.",
-    type=pathlib.Path,
-)
-parser.add_argument("--client", help="Path to the Web UI folder.", type=pathlib.Path)
-
-tools = parser.add_argument_group(title="Tools")
-tools.add_argument("--password-reset", help="Reset the password.", action="store_true")
-
-
-def run(*args, **kwargs):
-    """
-    Swing Music entry point
-    """
-    args = parser.parse_args()
-    args = vars(args)
-
-    config_parent = args["config"]
-    client_path = args["client"]
-
-    # INFO: Validate client path
-    if client_path is not None:
-        client_path = pathlib.Path(client_path).resolve()
-
-        if not client_path.exists():
-            print(
-                f"Client path {client_path} does not exist. Please provide a valid path"
-            )
-            sys.exit(1)
-        else:
-            # INFO: check if client path has index.html
-            if not (client_path / "index.html").exists():
-                print(
-                    f"Client path {client_path} does not contain an index.html file. Please provide a valid path"
-                )
-                sys.exit(1)
-
-    settings.Paths(config_parent=config_parent, client_dir=client_path)
-    AssetHandler.copy_assets_dir()
-    AssetHandler.setup_default_client()
-
-    setup_logger(debug=args["debug"], app_dir=settings.Paths().config_dir)
-
-    # handle tools
-    if args["password_reset"]:
-        swing_tools.handle_password_reset(config_parent)
-        sys.exit(0)
-
-    # start swingmusic
-    start_swingmusic(host=args["host"], port=args["port"])
-
-
-if __name__ == "__main__":
-    multiprocessing.freeze_support()
-    multiprocessing.set_start_method("spawn")
-    run()