fix: improve Swiss letter template localization and formatting

- Disable page numbering (pagenumber=false) to remove "Page 2" footer
- Add conditional German language support (babel with ngerman/german)
- German labels (Telefon, Anlagen) when texlive-lang-german is installed
- Graceful fallback to English labels when language package unavailable
- Update documentation to clarify language package as recommended

This addresses user feedback about English labels in German letters and unwanted page numbers on multi-page letters.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/.claude/templates/swiss-letter.tex

@@ -9,6 +9,7 @@
   fromalign=right,        % Sender address aligned right
   fromphone,              % Include phone number
   fromemail,              % Include email address
+  pagenumber=false,       % Disable page numbers
   version=last            % Use latest KOMA-Script features
 ]{scrlttr2}
 
@@ -32,6 +33,28 @@
 \providecommand{\tightlist}{%
   \setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}
 
+% ==================== LANGUAGE SUPPORT ====================
+% Try to load German language support if available
+% This provides proper German labels (Telefon, Anlagen) and hyphenation
+%
+% If german.ldf is found: Labels will be in German
+% If not found: Labels will be in English (Phone, encl)
+%
+% To install German support:
+% Ubuntu/Debian: sudo apt install texlive-lang-german
+% Arch: sudo pacman -S texlive-langgerman
+% macOS/Windows: Included in full TeX Live installation
+\IfFileExists{ngerman.ldf}{%
+  \usepackage[ngerman]{babel}
+}{%
+  \IfFileExists{german.ldf}{%
+    \usepackage[german]{babel}
+  }{%
+    % No German language files found
+    % Labels will be in English (Phone, encl) without language package
+  }
+}
+
 % ==================== SWISS LETTER CONFIGURATION ====================
 % Load Swiss Norm (SN) for proper address window positioning
 % This ensures the recipient address fits in standard Swiss envelope windows