Add phone-based EAN scanning, scanner server for cover upload, Vision-LLM integration

New features:
- EAN/Barcode can now be entered by typing or by photographing the CD sleeve;
  Vision-LLM (extract_barcode_from_image) reads the barcode from the photo
- Scanner server (port 8765) starts at the beginning of every album loop,
  serving both EAN barcode scanning and back cover upload via QR code
- Vision-LLM analyses back cover in background thread while ripping;
  priority: Vision-LLM > MusicBrainz > CDDB
- _find_abcde_mbid reads MBID from abcde temp dirs for CAA cover download
  even when the CD barcode is not linked in MusicBrainz
- Concrete copy-paste apply commands shown after each album in 'Next steps'
- _sanitize_name: whitelist approach (removes brackets and punctuation)
- qrcode added as dependency for terminal QR code display

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

tests/test_musicbrainz.py

@@ -160,11 +160,12 @@ class TestLookupByBarcode:
             patch("musiksammlung.musicbrainz.httpx.get", side_effect=responses),
             patch("musiksammlung.musicbrainz.time.sleep"),
         ):
-            album = lookup_by_barcode("0602557360561")
+            album, mbid = lookup_by_barcode("0602557360561")
 
         assert album.artist == "The Beatles"
         assert album.album == "Abbey Road"
         assert album.year == 1969
+        assert mbid == "abc-123"
 
     def test_raises_when_no_releases(self) -> None:
         empty = _mock_response({"releases": []})
@@ -173,7 +174,7 @@ class TestLookupByBarcode:
             patch("musiksammlung.musicbrainz.time.sleep"),
             pytest.raises(ValueError, match="Kein MusicBrainz-Eintrag"),
         ):
-            lookup_by_barcode("0000000000000")
+            lookup_by_barcode("0000000000000")  # raises before returning tuple
 
     def test_uses_first_release(self) -> None:
         barcode_data = {"releases": [{"id": "first-id"}, {"id": "second-id"}]}
@@ -182,11 +183,12 @@ class TestLookupByBarcode:
             patch("musiksammlung.musicbrainz.httpx.get", side_effect=responses) as mock_get,
             patch("musiksammlung.musicbrainz.time.sleep"),
         ):
-            lookup_by_barcode("1234567890123")
+            _album, mbid = lookup_by_barcode("1234567890123")
 
         # Zweiter Request muss die MBID des ersten Treffers verwenden
         second_call_url = mock_get.call_args_list[1][0][0]
         assert "first-id" in second_call_url
+        assert mbid == "first-id"
 
     def test_rate_limit_sleep_is_called(self) -> None:
         responses = [_mock_response(_BARCODE_RESPONSE), _mock_response(_RELEASE_RESPONSE)]
@@ -194,7 +196,7 @@ class TestLookupByBarcode:
             patch("musiksammlung.musicbrainz.httpx.get", side_effect=responses),
             patch("musiksammlung.musicbrainz.time.sleep") as mock_sleep,
         ):
-            lookup_by_barcode("0602557360561")
+            _album, _mbid = lookup_by_barcode("0602557360561")
 
         mock_sleep.assert_called_once()
         assert mock_sleep.call_args[0][0] >= 1.0
@@ -206,4 +208,4 @@ class TestLookupByBarcode:
             patch("musiksammlung.musicbrainz.httpx.get", side_effect=httpx.HTTPError("timeout")),
             pytest.raises(httpx.HTTPError),
         ):
-            lookup_by_barcode("0000000000000")
+            lookup_by_barcode("0000000000000")  # raises before returning tuple