chore(analytics): remove second batch of dead Amplitude events

Removes ~45 zero-callsite event definitions: legacy OAuth flows,
dead create-account stubs, wAUDIO transfer events, abandoned Social Proof
feature, playlist library UI events, performance instrumentation that never
shipped, and more. Follows up on #14304.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: dylanjeffers