Release: 0.7.0

Added

• Added Dachsparren-Rechner with live CAD-based visualization for roof geometry workflows
• Added Winkelrechner for triangle and angle calculations used in daily build planning
• Added About page with project vision and creator background

Changed

• Reorganized navigation under Tools with groups: Statik, Zimmerer, Hilfsmittel
• Moved Discord access to a minimal floating button plus footer link
• Redesigned footer with grouped links to key calculators and tools
• Updated homepage card icons to clarify Pfosten and Fundament tool context