Rewrite songbook as pure LaTeX project (Carmina Leonis style)

Replace the Kotlin/Gradle multi-module pipeline with a pure LaTeX
songbook using the leadsheets package and LuaLaTeX. Style matches
the Carmina Leonis (CL6) scout songbook: Fraktur titles, chords
above lyrics, metadata at page bottom, reference book footer.

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

songbook.tex

@@ -0,0 +1,31 @@
+% songbook.tex - Pfadfinder Liederbuch
+\documentclass[a5paper, 10pt, twoside]{article}
+
+\usepackage{songbook-style}
+
+\begin{document}
+
+% --- Title page ---
+\begin{titlepage}
+  \centering
+  \vspace*{3cm}
+  {\Huge\bfseries Pfadfinder Liederbuch\par}
+  \vspace{1cm}
+  {\Large Beispiel-Ausgabe\par}
+  \vspace{2cm}
+  {\large 1. Auflage, 2026\par}
+  \vfill
+\end{titlepage}
+
+% --- Table of Contents ---
+\tableofcontents
+\clearpage
+
+% --- Songs (alphabetical) ---
+\input{songs/abend-wird-es-wieder}
+\input{songs/auf-auf-zum-froehlichen-jagen}
+\input{songs/die-gedanken-sind-frei}
+\input{songs/hejo-spann-den-wagen-an}
+\input{songs/kein-schoener-land}
+
+\end{document}