Rename to Carmina Leonis and add original foreword text

- Rename "Liederbuch" to "Carmina Leonis" in TOC header, song
  footer, and title page
- Replace placeholder foreword with original CL6 introductory text
- Update title page to "Carmina Leonis, 7. Auflage, 2026"

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

songbook-style.sty

@@ -1,5 +1,5 @@
 \NeedsTeXFormat{LaTeX2e}
-\ProvidesPackage{songbook-style}[2026/04/01 Pfadfinder Liederbuch Style]
+\ProvidesPackage{songbook-style}[2026/04/01 Pfadfinder Carmina Leonis Style]
 
 % --- Core packages ---
 \RequirePackage{fontspec}
@@ -179,7 +179,7 @@
   & \rotheader{SwA}
   & \rotheader{Barde}
   & \rotheader{LiBock}
-  & \rotheader{\normalsize Lieder-\newline\normalsize buch} \\
+  & \rotheader{\normalsize Carmina\newline\normalsize Leonis} \\
   \hline
   \endfirsthead
   & \rotheader{BuLiBu}
@@ -187,7 +187,7 @@
   & \rotheader{SwA}
   & \rotheader{Barde}
   & \rotheader{LiBock}
-  & \rotheader{\normalsize Lieder-\newline\normalsize buch} \\
+  & \rotheader{\normalsize Carmina\newline\normalsize Leonis} \\
   \hline
   \endhead
   \InputIfFileExists{\jobname.songtoc}{}{}%
@@ -221,7 +221,7 @@
   \vspace{3mm}%
   \begingroup\footnotesize\centering
     \begin{tabular}{cccccc}
-      BuLiBu & CL (gr.) & SwA & Barde & LiBock & Liederbuch \\
+      BuLiBu & CL (gr.) & SwA & Barde & LiBock & Carmina Leonis \\
       \ifsongproperty{bulibu}{\songproperty{bulibu}}{} &
       \ifsongproperty{cl}{\songproperty{cl}}{} &
       \ifsongproperty{swa}{\songproperty{swa}}{} &