- ARCHITECTURE.md: comprehensive project documentation (868 lines)
covering all 21 chapters (data model, services, endpoints,
chat pipeline, tool system, agents, memory, skills, telegram,
cronjobs, krea, auth, workspace, deployment, config)
- ARCHITECTURE_QUICK.md: compact quick-reference (223 lines)
for fast lookups during development
- chat.css: add .msg.user.markdown pre selector so code blocks
in user messages get correct background color (was only on code)