RXWatcherandClaude Opus 4.7
1a0701f585
First of six sub-plans for the absorption. Six tasks: a discovery audit that resolves the spec's Risk questions, four idempotent SQL migrations (abs_sessions, podcast_feeds, media_libraries.kind, audiobooks.enabled feature flag), and an empty-but-compiling internal/audiobooks package scaffolded into cmd/silo. Lands as a strict no-op for users (feature flag defaults to false). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>