Migrate the last three callers of the FS-scanning dependency helpers to the
CRDT-direct equivalents and delete the dead helpers:
- agents/pool/auto_assign/story_checks.rs: has_unmet_dependencies and
check_archived_dependencies now wrap check_unmet_deps_crdt /
check_archived_deps_crdt directly. Tests rewritten to seed the CRDT.
- http/mcp/story_tools/story/update.rs: bug-503 archived-dep warning now
reads from CRDT instead of scanning 6_archived.
- agents/pool/pipeline/advance/helpers.rs: resolve_qa_mode_from_store is
CRDT-only (the FS fallback for content-store-empty stories is gone).
- io/story_metadata/parser.rs: resolve_qa_mode_from_content removed.
- io/story_metadata/deps.rs: check_unmet_deps and dep_is_done deleted,
along with the unused check_unmet_deps_from_list helper.
- io/story_metadata/mod.rs: re-exports trimmed accordingly.
check_archived_deps_from_list survives because story-creation still calls
it before the CRDT entry exists (used from story_tools/story/create.rs).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>