feat: auto-rename album directory after in-place apply

After all file operations (rename, tag, cover, playlist), apply now
renames the album root directory to match album.json metadata:

- input_dir = CD1/CD2 etc.: parent directory is renamed automatically
  e.g. Kärntner_Doppelsextett/ → Du_Berührst_Mi_20_Jahre_Kärntner_Doppelsextett/
- input_dir = album root: a hint with the mv command is printed instead
  (avoids renaming an actively used path)
- Existing directory with target name: warning, no rename

Also: _sanitize_filename() in organizer.py made public (sanitize_filename),
used consistently across organizer, playlist and cli modules.

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

src/musiksammlung/cli.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import json
 import logging
+import re
 from pathlib import Path
 
 import httpx
@@ -16,7 +17,12 @@ from musiksammlung.llm_parser import parse_tracklist
 from musiksammlung.models import Album
 from musiksammlung.musicbrainz import lookup_by_barcode
 from musiksammlung.ocr import ocr_images
-from musiksammlung.organizer import apply_mapping, build_mapping, check_disc_counts
+from musiksammlung.organizer import (
+    apply_mapping,
+    build_mapping,
+    check_disc_counts,
+    sanitize_filename,
+)
 from musiksammlung.playlist import generate_playlist
 from musiksammlung.ripper import RipperConfig, interactive_rip
 from musiksammlung.tagger import embed_album_cover, tag_album
@@ -77,6 +83,48 @@ def _scan_to_album(
         )
 
 
+_CD_SUBDIR = re.compile(r"^CD\d+$", re.IGNORECASE)
+
+
+def _rename_album_dir_inplace(input_dir: Path, album: Album) -> None:
+    """Benennt das Album-Wurzelverzeichnis nach den Metadaten um.
+
+    Muss als allerletzter Schritt aufgerufen werden, nachdem Tags,
+    Cover und Playlist bereits gesetzt wurden.
+
+    Logik:
+    - input_dir heißt 'CD1', 'CD2' etc. → Album-Wurzel = input_dir.parent,
+      Umbenennung erfolgt automatisch.
+    - Sonst (input_dir ist selbst das Album-Wurzelverzeichnis) → nur Hinweis
+      ausgeben, da ein Umbenennen des aktiven Verzeichnisses vermieden wird.
+    """
+    abs_input = input_dir.resolve()
+    desired = sanitize_filename(album.folder_name)
+
+    if _CD_SUBDIR.match(abs_input.name):
+        # CD-Unterverzeichnis übergeben → Elternverzeichnis umbenennen
+        album_root = abs_input.parent
+        if album_root.name == desired:
+            return  # bereits korrekt
+        new_path = album_root.parent / desired
+        if new_path.exists():
+            typer.echo(
+                f"Warnung: Zielverzeichnis '{desired}' existiert bereits — "
+                "Verzeichnis nicht umbenannt.",
+                err=True,
+            )
+            return
+        album_root.rename(new_path)
+        typer.echo(f"Verzeichnis umbenannt: {album_root.name}  →  {desired}")
+    else:
+        # Album-Wurzelverzeichnis direkt übergeben → nur Hinweis
+        if abs_input.name != desired:
+            typer.echo(
+                f"Tipp: Verzeichnis manuell umbenennen:\n"
+                f"  mv '{abs_input.name}' '{desired}'"
+            )
+
+
 def _check_disc_counts_or_exit(album: Album, input_dir: Path, album_json: Path) -> None:
     """Prüft Disc-Zählungen und beendet das Programm bei Abweichungen."""
     checks = check_disc_counts(album, input_dir)
@@ -251,6 +299,9 @@ def apply(
         embed_album_cover(album, album_dir, cover)
     generate_playlist(album, album_dir)
 
+    if in_place:
+        _rename_album_dir_inplace(input_dir, album)
+
     typer.echo(f"Fertig! Album liegt in: {album_dir}")
 
 

src/musiksammlung/organizer.py

@@ -37,7 +37,7 @@ class DiscCheck:
         return max(0, self.json_track_count - self.audio_file_count)
 
 
-def _sanitize_filename(name: str) -> str:
+def sanitize_filename(name: str) -> str:
     """Ersetzt Sonderzeichen und Leerzeichen durch Unterstriche.
 
     Buchstaben (inkl. Umlaute), Ziffern und bestehende Unterstriche bleiben erhalten.
@@ -104,8 +104,8 @@ def build_mapping(
         album_dir = input_dir
     else:
         assert output_root is not None, "output_root erforderlich wenn nicht in_place"
-        artist_dir = _sanitize_filename(album.artist)
-        album_dir = output_root / artist_dir / _sanitize_filename(album.folder_name)
+        artist_dir = sanitize_filename(album.artist)
+        album_dir = output_root / artist_dir / sanitize_filename(album.folder_name)
 
     mapping: dict[Path, Path] = {}
     multi_disc = len(album.discs) > 1
@@ -130,8 +130,8 @@ def build_mapping(
             )
 
         for audio_file, track in zip(audio_files, disc.tracks):
-            safe_title = _sanitize_filename(track.title)
-            safe_artist = _sanitize_filename(track.artist or album.artist)
+            safe_title = sanitize_filename(track.title)
+            safe_artist = sanitize_filename(track.artist or album.artist)
             new_name = f"{track.track_number:02d}_-_{safe_title}_-_{safe_artist}{audio_file.suffix}"
             mapping[audio_file] = target_dir / new_name
 

src/musiksammlung/playlist.py

@@ -6,7 +6,7 @@ import logging
 from pathlib import Path
 
 from musiksammlung.models import Album
-from musiksammlung.organizer import _sanitize_filename
+from musiksammlung.organizer import sanitize_filename
 
 logger = logging.getLogger(__name__)
 
@@ -20,7 +20,7 @@ def generate_playlist(album: Album, album_dir: Path) -> Path:
     Returns:
         Pfad zur erzeugten Playlist-Datei.
     """
-    playlist_name = _sanitize_filename(album.album) + ".m3u"
+    playlist_name = sanitize_filename(album.album) + ".m3u"
     playlist_path = album_dir / playlist_name
     multi_disc = len(album.discs) > 1
 
@@ -33,7 +33,7 @@ def generate_playlist(album: Album, album_dir: Path) -> Path:
             disc_prefix = ""
 
         for track in disc.tracks:
-            safe_title = _sanitize_filename(track.title)
+            safe_title = sanitize_filename(track.title)
             # Audiodatei im Zielverzeichnis finden
             pattern = f"{track.track_number:02d}_-_{safe_title}*"
             if multi_disc: