Add Goethe filler page and clean up image artifacts

- Insert Goethe poem illustration (img-000.jpg) as filler page
  between TOC and first song (matching reference layout)
- Remove 10 alpha mask/tiny artifact images

The remaining ~65 unused images are mostly on song pages where
CL number matching failed — they need manual assignment.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

songbook.tex

@@ -90,6 +90,9 @@ mitgewirkt haben, ganz besonders an Andi, der auch diese Auflage des
 \pagenumbering{arabic}
 \setcounter{page}{1}
 
+% --- Filler illustration (Goethe poem) ---
+\fillerpage{images/img-000.jpg}
+
 % --- Songs (alphabetical, auto-generated from import) ---
 \input{all-songs}