- Add hard rule: only listings returned by MCP tools may be reported;
  no invented addresses, prices, contacts, or 'similar' examples.
- Replace weak fallback with mandatory multi-attempt fallback order
  (switch search type, drop filters, simplify query, widen location,
  minimal search) before reporting no results.
- Expand filter list to full MetadataFilters set with enum values.
- Add explicit mapping of vague user phrases to concrete filters
  (e.g. 'с ремонтом' -> renovation_status, 'у метро' -> metro_distance).
- Add forbidden query patterns and good/bad Ukrainian query examples.
- Sync MCP server instructions with same anti-hallucination and filter
  rules, including example queries.