feat(browser): complete inclusive personalization demo

[Phloraxx]

Summary

• add an AI-personalized Learn Me OOBE across six functional support areas, with a focused mascot-led comfort UI
• add standards-backed personalized page scanning, explainable AURA Fit scoring, and before/after evidence
• strengthen reversible local and semantic page adaptation plus deterministic Talk to AURA page actions
• add cloud retry/friendly fallback behavior and native macOS speech support
• add a one-click event launcher and the final 80-second judge demo with its recording runbook
• remove direct Corepack dependencies from repository scripts so plain pnpm works on the event Mac

Validation

• pnpm lint
• pnpm typecheck
• pnpm test — 153 active tests passed, 2 skipped
• pnpm build
• pnpm browser:test:e2e — 3 Electron journeys passed
• pnpm browser:package:mac — successful darwin-arm64 package

Publish hygiene

• .env remains ignored
• no OpenAI key is committed
• raw and oversized video intermediates remain ignored
• only the final compressed demo video and editable demo source files are included