Verify GitP sources for podcast garden proxies #181

Gitpa's episode proxies depend on source session and asset pages still under review in PR #178. Ensure the source data, asset URLs, and publication documentation form a consistent source for exact-name proxies.

Audit session and asset sources and public media URLs; address source-side defects discovered by the Gitpa presentation work; document the source/publication boundary and exact source paths; preserve protected tags and block IDs. Continue #178 and pair with codekiln/gitpa#12.

The shared Proxy/Page and Mise Task model and sync implementation are owned by another Codex session; coordinate through the existing shared plan without duplicating that work.