Wires the existing "AI Assistent" button in the TopBar and adds a 420px
slide-in drawer with context-aware suggestions, message thread, loading
animation, and action cards requiring manual confirmation. Template-based
mock service returns German-language answers keyed by route + question
keywords — no real LLM calls, no invented facts.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>