The old README was stale in a way that actively misled: it claimed a SQLite cache at .cache/tourmaline.db that doesn't exist anywhere in the codebase (actual caching is an in-memory server Map + localStorage client cache, both non-persistent — there's no database), and its project-structure tree listed roughly a quarter of the files that actually exist (no personality/story-recap/comparison/recommendations analysis, no share cards, four fewer route groups). Rewrote to reflect the real architecture (client-side aggregation, server-only for third-party API proxying) and documented everything added this session: compare, recommendations, track previews, listening context, since-your-last-visit, and all four share card types. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>