feat: integrate First8 Marketing hyper-personalization system

Enhanced Umami Analytics with First8 Marketing integration for
hyper-personalized recommendation engine.

Database Enhancements:
- PostgreSQL 17 with Apache AGE 1.6.0 (graph database)
- TimescaleDB 2.23.0 (time-series optimization)
- Extended schema for WooCommerce event tracking
- Custom tables for recommendation engine integration

Features Added:
- Real-time ETL pipeline to recommendation engine
- Extended event tracking (WordPress + WooCommerce)
- Graph database for relationship mapping
- Time-series optimization for analytics queries
- Custom migrations for hyper-personalization

Documentation:
- Updated README with integration details
- Added system architecture documentation
- Documented data flow and components
- Preserved original Umami Software credits

Integration Components:
- First8 Marketing Track plugin (event tracking)
- Recommendation Engine (ML backend)
- First8 Marketing Recommendation Engine plugin (presentation)

Status: Production-ready
Version: Based on Umami latest + First8 Marketing enhancements

db/postgresql/rollback/001_rollback_woocommerce_fields.sql

@@ -0,0 +1,34 @@
+-- Rollback Migration: Remove WooCommerce and Enhanced Tracking Fields
+-- Created: 2025-01-15
+-- Description: Removes WooCommerce e-commerce tracking fields and enhanced engagement metrics from website_event table
+-- WARNING: This will permanently delete all WooCommerce tracking data!
+
+-- Drop indexes first (must be done before dropping columns)
+DROP INDEX IF EXISTS idx_website_event_wc_product;
+DROP INDEX IF EXISTS idx_website_event_wc_category;
+DROP INDEX IF EXISTS idx_website_event_wc_order;
+DROP INDEX IF EXISTS idx_website_event_wc_revenue;
+DROP INDEX IF EXISTS idx_website_event_engagement;
+
+-- Remove WooCommerce e-commerce tracking fields
+ALTER TABLE website_event
+  DROP COLUMN IF EXISTS wc_product_id,
+  DROP COLUMN IF EXISTS wc_category_id,
+  DROP COLUMN IF EXISTS wc_cart_value,
+  DROP COLUMN IF EXISTS wc_checkout_step,
+  DROP COLUMN IF EXISTS wc_order_id,
+  DROP COLUMN IF EXISTS wc_revenue;
+
+-- Remove enhanced engagement tracking fields
+ALTER TABLE website_event
+  DROP COLUMN IF EXISTS scroll_depth,
+  DROP COLUMN IF EXISTS time_on_page,
+  DROP COLUMN IF EXISTS click_count,
+  DROP COLUMN IF EXISTS form_interactions;
+
+-- Log rollback completion
+DO $$
+BEGIN
+  RAISE NOTICE 'Rollback complete: WooCommerce and enhanced tracking fields removed from website_event table';
+END $$;
+