Add enterprise growth APIs, billing, admin UI, and test suite.

Add SuperAdmin retailer API keys with priority over env and free scraping.

Add Platform Presence Scanner for URL import distribution scoring.

feat: proper visitor analytics system - New Visitor model (visitor_uid + fingerprint fallback, first_seen/last_seen/page_views, geo, device) - VisitorRepository with upsert + analytics queries - visitor_tracker.py: record_visitor() upserts on every session/init - session/init accepts visitor_uid in request body (HF-Spaces iframe-safe, no cookies) - 4 new analytics endpoints: /visitors /geo /devices /sessions/stats - geo.py: region extraction + X-Real-IP support - DB migration: visitor_uid column on chat_sessions - ARCHITECTURE.md updated

Phase 1: Add Conversations Viewer, Custom Q&A Manager, Export Center — 15 new API endpoints, 3 new admin pages, CustomQA model, message annotations, flagging, search, CSV import/export

Restructure project for HF Spaces deployment