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

swingmusic/run.py

@@ -0,0 +1,27 @@
+# Launcher script
+import sys
+import zipfile
+import multiprocessing
+from pathlib import Path
+import swingmusic.__main__ as app
+
+if __name__ == "__main__":
+	# Fixed: freeze_support() must be called immediately to prevent 
+	# recursive process spawning and ArgumentParser errors on Windows EXE.
+    multiprocessing.freeze_support()
+    
+    # this entry should only be used by pyinstaller.
+    # add freeze support here as pyinstaller uses this entry
+
+    if getattr(sys, "frozen", False) and hasattr(sys, "_MEIPASS"):
+        # INFO: extract client.zip to sys._MEIPASS
+        with zipfile.ZipFile(sys._MEIPASS + "/client.zip", "r") as zip_ref:
+            zip_ref.extractall(sys._MEIPASS)
+
+        client = Path(sys._MEIPASS) / "client"
+        client_str = str(client)
+
+        sys.argv.extend(["--client", client_str])
+        sys.orig_argv.extend(["--client", client_str])
+
+    app.run()