feat(ecosystem): adopt hub-core dependency and CI pin gate (CORE-WP-0009)

Import slugify_or_default from hub-core, add contract tests, vendor hub-core in
Docker/Forgejo CI, document metadata isolation and pagination deferral, and
align INTENT/SCOPE with three-repo stack.

docs/specs/data-model.md

@@ -62,7 +62,16 @@ consumers need during bootstrap and smoke testing:
 - Store only hashes, prefixes, labels, and non-secret lifecycle metadata.
 - Record row counts, relationship checks, and fixture replays for every migration batch.
 
-## Open Questions
+## Resolved decisions (2026-07-09, CUST-WP-0057)
 
-- Whether Core Hub owns the canonical workplan task tables or continues reading from State Hub until cutover.
-- Whether Inter-Hub admin-only entities should be migrated as historical records or redesigned as Core Hub-native resources.
+- **Workplan/task tables:** State Hub remains canonical. Core Hub may index and
+  display workplan data via HTTP ingestion later; it does not fork tables in
+  this consolidation lane. See `the-custodian/docs/hub-ecosystem-architecture.md`.
+- **Inter-Hub admin entities:** Migrated as historical records where consumers
+  depend on identifiers; deferred protected surfaces stay empty compatibility
+  collections until a consumer requires them.
+
+## Open questions
+
+- Whether Core Hub adds a read-model ingestion path from State Hub progress/messages
+  (`STATE-WP-0074`) or remains framework-only for coordination data.