Introduces build_selective_context() which loads only the data categories
requested by the Smart Router (companies_all, companies_filtered:CAT,
companies_single:NAME, events, news, classifieds, forum, company_people,
registered_users, social_media, audits) instead of loading everything for
every query. Basic stats and conversation history are always included.
Company compact dict format mirrors nordabiz_chat._company_to_compact_dict()
exactly for full _query_ai() compatibility.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
