Event call sites (product_view, add_to_cart, checkout_start, purchase)
were only passing visitor_hash and pathname, leaving browser, OS, screen
size and country nil. Add AnalyticsHook.attrs/1 helper to extract common
analytics fields from socket assigns, and use it in all LiveView event
call sites. Checkout controller reads the same fields from the session.
Also fix plug analytics test to clear stale events before assertions.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Three-layer pipeline: Plug for all HTTP requests (no JS needed), LiveView
hook for SPA navigations, JS hook for screen width. ETS-backed buffer
batches writes to SQLite every 10s. Daily-rotating salt for visitor hashing.
Includes admin dashboard with date ranges, visitor trends, top pages,
sources, devices, and e-commerce conversion funnel. Oban cron for 12-month
data retention.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
