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/lib/home/recentlyplayed.py

@@ -1,35 +0,0 @@
-from datetime import datetime
-
-from swingmusic.db.userdata import ScrobbleTable
-from swingmusic.models.playlist import Playlist
-from swingmusic.lib.playlistlib import get_first_4_images
-from swingmusic.utils.dates import (
-    create_new_date,
-    date_string_to_time_passed,
-)
-
-from swingmusic.store.tracks import TrackStore
-
-
-def get_recently_played_playlist(limit: int = 100):
-    playlist = Playlist(
-        id="recentlyplayed",
-        name="Recently Played",
-        image=None,
-        last_updated="Now",
-        settings={},
-        trackhashes=[],
-    )
-
-    scrobbles = ScrobbleTable.get_all(None, 100)
-    tracks = TrackStore.get_tracks_by_trackhashes(
-        [scrobble.trackhash for scrobble in scrobbles]
-    )
-
-    date = datetime.fromtimestamp(tracks[0].lastplayed)
-    playlist._last_updated = date_string_to_time_passed(create_new_date(date))
-
-    images = get_first_4_images(tracks=tracks)
-    playlist.images = images
-
-    return playlist, tracks