docs(ecosystem): complete hub stack consolidation (CUST-WP-0057)

Publish ecosystem architecture, event mapping, capability bridge, and async-base
decision docs; add cross-repo regression script; update extraction boundary and
bootstrap status; archive WP-0058 touch-ups.

docs/hub-core-extraction-boundary.md

@@ -245,11 +245,20 @@ to import it:
 5. `cd /home/worsch/state-hub && make test` remains green before and after the
    editable `hub-core` dependency is introduced.
 
+## Ecosystem composition (CUST-WP-0057)
+
+hub-core is the **library layer** only. It does not own:
+
+- core-hub framework tables (`hubs`, `widgets`, `hub_capability_manifests`, …)
+- state-hub dev-hub tables (workplans, tasks, topics, …)
+
+Integration canon: `docs/hub-ecosystem-architecture.md`
+
 ## Next Step
 
-**CUST-WP-0048** is finished; **CUST-WP-0025-T08** is done. Proceed to Phase 2
-dev-hub rename (**CUST-WP-0025-T09+**): MCP server name, config migration, and
-integration-point renames. Optional follow-up extractions (not blocking rename):
+**CUST-WP-0048** is finished; **CUST-WP-0025-T08** is done. Ecosystem
+consolidation continues under **CUST-WP-0057** (compose hub-core, state-hub,
+core-hub without merging repos). Optional follow-up extractions:
 
 - map State Hub `ProgressEvent` foreign keys into `subject_refs`
 - map CapabilityRequest workplan/task columns into JSON context fields