Stream Feeds - v2 to v3 sync mapping

Read first (every session): Glob ../stream/SKILL.md and Read ../stream/RULES.md (both ship with this skill). The Secrets rule governs every step below: the app secret never enters the conversation. RULES.md also carries the Peer skills procedure for installing and invoking any other pack skill on demand.

Produce the mapping object for an app's v2 -> v3 sync configuration by looking at what the app's v2 data actually contains, rather than at what anyone believes it contains.

One mapping serves both migration paths - the live syncer and the bulk exporter read the same configuration. Getting it right once fixes both; getting it wrong breaks both in the same way.

Workflow

1. Get credentials into the environment