v0.1.0-alpha.5 — analytics channel

Unsampled analytics channel — set analytics: true (or let @telemetryBrowser emit data-analytics when the Laravel package's analytics is on). Emits events (never sampled away) to the ingest endpoint's events key:

• SPA page views on history navigations the server never sees, with document.referrer + previous path.
• Engagement — visible time + scroll depth, summarised on page hide.
• track(name, properties) for custom conversions/goals.
• Screen size + devicePixelRatio device dimensions.