Add song aliases to TOC and fix page numbering

- 82 songs get alias entries (alternate titles/opening lines) shown
  in italic in the TOC, pointing to the same page as the main title
- Front matter (title, foreword, TOC) has no page numbers
- Song pages start at page 1
- Aliases extracted from reference PDF (CL6) TOC by title matching

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

songbook.tex

@@ -5,6 +5,9 @@
 
 \begin{document}
 
+% --- Front matter: no page numbers ---
+\pagenumbering{gobble}
+
 % --- Title page ---
 \begin{titlepage}
   \centering
@@ -83,6 +86,10 @@ mitgewirkt haben, ganz besonders an Andi, der auch diese Auflage des
 \printsongtoc
 \clearpage
 
+% --- Reset page numbering: first song = page 1 ---
+\pagenumbering{arabic}
+\setcounter{page}{1}
+
 % --- Songs (alphabetical, auto-generated from import) ---
 \input{all-songs}