Refactor the project-scoped serve/propose internals into collection-grained
helpers (_list_rfcs_for_collection, _get_rfc_for_collection,
_propose_into_collection); add routes under
/api/projects/<id>/collections/<cid>/rfcs[/<slug>|/propose]. Propose writes
the entry under the target collection's <subfolder>/rfcs via a new rfcs_dir
param on bot.open_idea_pr. Default-collection routes preserved as wrappers.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
refresh_meta_repo now iterates a project's collections and keys cached_rfcs by
collection_id; the default collection (subfolder '') keeps the shipped rfcs/
root path. N=1 default path unchanged (469 green).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>