Summary

• Reorganize docs from feature-oriented flat list (26 guide pages) to progressive disclosure structure: Introduction -> Core Concepts -> Guides -> Advanced -> Reference
• Rewrite introduction as value proposition instead of feature dump
• Add "Why Zeph?" page with differentiators (token efficiency, hybrid inference, privacy)
• Replace Quick Start with scenario-driven "First Conversation" onboarding
• Add Core Concepts section (skills, memory, providers, tools) as gentle entry point
• Split guides into scenario-based (cloud provider, Telegram, custom skills) and deep dives (advanced/)
• Merge related pages: audio+vision -> multimodal, daemon+scheduler -> daemon
• Move reference material (CLI, config, feature flags, security) to dedicated Reference section
• Update all internal cross-references

Test plan

• mdbook build passes with no errors or warnings
• All internal links resolve correctly
• New user can follow Introduction -> First Conversation -> Core Concepts path
• Existing deep-dive content preserved in Advanced section