Add Docker deployment, EU AI Act slide, and chapter name in HUD

Serves the deck via a small nginx container (docker compose up -d).
The Dockerfile copies files individually rather than COPY . . so the
speaker notes, design docs and local backups stay out of the image.

Deck grows to 44 slides: adds a Vibe Coding slide covering AI-assisted
programming, an EU AI Act slide with the four risk tiers, and expands
the outlook from three to six trends. The HUD now also shows the
current chapter name, resolved from the slide manifest.

.dockerignore

@@ -0,0 +1,12 @@
+# Nichts davon gehört ins Image — schützt vor versehentlichem Ausliefern
+# der Sprechernotizen und hält den Build-Context klein.
+.git
+.gitignore
+.DS_Store
+*.md
+ki-verstehen.backup-*.html
+ki-verstehen-bearbeitet.html
+deck-template.html
+docker-compose.yml
+Dockerfile
+.dockerignore