docs: update system map

[shchukins]

Summary

• update docs/ai/SYSTEM_MAP.md so it reflects the current deterministic architecture, model layers, and product loops
• separate implemented, partial, planned, and future layers across ingestion, storage, normalization, readiness, recommendation, delivery, feedback, and calibration
• add an end-to-end Mermaid system flow plus explicit current gaps and repo-visible UI/operations state

Verification

• reviewed repo docs, backend structure, readiness API docs, notification/feedback docs, and current repo-visible iOS surface
• no production code changed