feat: Lyrics-Funktion und Install-Script

- Lyrics-Ansicht mit Taste l (lrclib.net API)
- Install-Script fuer systemweite Installation
- README aktualisiert

spotify_cli/client.py

@@ -197,5 +197,43 @@ class SpotifyClient:
         return self._get("/me")
 
 
+class LyricsClient:
+    LRCLIB_URL = "https://lrclib.net/api"
+
+    def get_lyrics(self, track_name, artist_name, album_name=None, duration_ms=None):
+        import requests as req
+
+        params = {
+            "track_name": track_name,
+            "artist_name": artist_name,
+        }
+        if album_name:
+            params["album_name"] = album_name
+        if duration_ms:
+            params["duration"] = duration_ms // 1000
+
+        try:
+            resp = req.get(f"{self.LRCLIB_URL}/get", params=params, timeout=5)
+            if resp.status_code == 200:
+                data = resp.json()
+                return data.get("syncedLyrics") or data.get("plainLyrics")
+        except Exception:
+            pass
+
+        try:
+            resp = req.get(f"{self.LRCLIB_URL}/search", params={
+                "q": f"{track_name} {artist_name}"
+            }, timeout=5)
+            if resp.status_code == 200:
+                results = resp.json()
+                if results:
+                    data = results[0]
+                    return data.get("syncedLyrics") or data.get("plainLyrics")
+        except Exception:
+            pass
+
+        return None
+
+
 class TokenExpired(Exception):
     pass