Add cycle-5 audit plans (checkout return URLs, scripts, Docker dedupe, LLM hygiene)

Commit notes

Cycle-5 focused audit: UX gotchas, LLM usage, embedding pipeline, performance, script consistency, and Docker duplication. LLM and CLAP embedding paths came back clean; plans 014-017 cover the real findings.

Co-Authored-By: Claude Fable 5 <[email redacted]> Claude-Session: [private session redacted]