Enhance lyric search functionality by improving line splitting logic and adding multi-line matching for subsearch. Update cache handling to ensure confidence threshold is respected before returning results.

lyric_search/sources/cache.py

@@ -343,15 +343,19 @@ class Cache:
                             )
                         else:
                             best_match = (result_tracks[0], 100)
-                        if not best_match or confidence < 90:
+                        if not best_match:
                             return None
                         (candidate, confidence) = best_match
+                        if confidence < 90:
+                            return None
                         logging.info("Result found on %s", self.label)
                         matched = self.get_matched(
                             sqlite_rows=results,
                             matched_candidate=candidate,
                             confidence=confidence,
                         )
+                        if matched is None:
+                            return None
                         time_end: float = time.time()
                         time_diff: float = time_end - time_start
                         matched.time = time_diff