Improve _is_classical(): genre keywords + composer list as primary signals

Previously any albumartist≠track_artist triggered classical naming, causing
false positives for jazz compilations, folk samplers, pop albums with
multiple featured artists. Now requires explicit confirmation:
- Genre contains a classical keyword (classical, baroque, opera, symphon …)
- OR track_artist name contains a known composer (Bach, Mozart, Beethoven …)
Pure name-inequality alone no longer triggers the Performer-Composer-Work schema.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

executor.py

@@ -42,21 +42,52 @@ def _safe_name(s: str) -> str:
     return re.sub(r"\s+", "_", s).strip("._-")
 
 
+_CLASSICAL_GENRE_KEYWORDS = {
+    "classical", "klassik", "baroque", "barock", "romantic", "romantik",
+    "opera", "oper", "operetta", "operette", "chamber", "kammermusik",
+    "symphon", "concerto", "oratorio", "sacred", "kirchenmusik",
+    "renaissance", "medieval", "contemporary classical",
+}
+
+_CLASSICAL_COMPOSER_KEYWORDS = {
+    # Bekannte Komponisten als Signal (Nachname reicht)
+    "bach", "beethoven", "mozart", "handel", "haydn", "schubert", "brahms",
+    "chopin", "liszt", "schumann", "wagner", "verdi", "puccini", "vivaldi",
+    "telemann", "buxtehude", "monteverdi", "palestrina", "purcell",
+    "mahler", "bruckner", "dvorak", "tchaikovsky", "tschaikowski",
+    "debussy", "ravel", "satie", "strauss", "sibelius", "grieg",
+}
+
+
 def _is_classical(albumartist: str, track_artist: str, genre: str) -> bool:
     """
-    Classical schema applies when performer (albumartist) ≠ composer (track_artist),
-    which covers both 'real' classical music and jazz-on-classical-themes albums.
-    Genre keyword matching is used as additional signal but not required.
+    Klassik-Schema (Performer_-_Komponist_-_Werk) wird angewendet wenn:
+    1. Genre explizit klassisch ist, ODER
+    2. track_artist ist ein bekannter Komponist (und ≠ albumartist), ODER
+    3. albumartist ≠ track_artist UND beide sind bekannte Komponistennamen.
+    Reine Performer≠Komponist-Heuristik ohne Genre-Bestätigung ist abgeschaltet
+    (zu viele Falschpositive bei Samplern, Jazz, Volksmusik).
     """
     aa = (albumartist or "").casefold().strip()
     ta = (track_artist or "").casefold().strip()
+    g = (genre or "").casefold().strip()
+
     if not aa or aa in ("various artists", "unknown artist", "unknown"):
         return False
     if not ta or ta in ("unknown artist", "unknown"):
-        return False  # placeholder, not a real composer
+        return False
     if aa == ta:
         return False
-    return True  # performer ≠ composer → classical naming
+
+    # Primäres Signal: Genre-Keyword
+    if any(kw in g for kw in _CLASSICAL_GENRE_KEYWORDS):
+        return True
+
+    # Sekundäres Signal: track_artist enthält bekannten Komponistennamen
+    if any(kw in ta for kw in _CLASSICAL_COMPOSER_KEYWORDS):
+        return True
+
+    return False
 
 
 def _proposed_filename(