Adds Grounding, Reasoning-Modelle, Token/Parameter examples, an
autocomplete mini-game, and a Copilot agent-building walkthrough with
a live chat-demo payoff. Adds Sprecher.md with per-slide speaker
cards. Fixes malformed data-def attributes and stray baked-in
active/visible classes left over from in-browser edit-mode sessions,
and stops the local save-in-place backups from being tracked.
Adds the complete "KI verstehen" presentation (36 slides), the
Präsentations-Konfigurator (config.html + slides-manifest.js) for
curating which slides to show, and updates DESIGN.md/PATTERNS.md/
deck-template.html to reflect the new house font (General Sans) and
newly established patterns (chapter dividers, term tooltips, the
mitmach game, ambient sound, and the slide configurator).
