feat(ecosystem): hub-core library lane for three-repo stack (HUB-WP-0003)

Add slugify_or_default for core-hub parity, bump to 0.2.0, document ecosystem
position in INTENT/SCOPE/README, wire capability relations to state-hub and
core-hub, and extend utils tests. Part of CUST-WP-0057 consolidation.

INTENT.md

@@ -1,9 +1,9 @@
 # INTENT — hub-core
 
 **Project:** `hub-core`  
-**Domain:** `inter_hub`  
-**Status:** Active extraction (CUST-WP-0025)  
-**Updated:** 2026-06-16
+**Domain:** `infotech`  
+**Status:** Active — library anchor for hub ecosystem (`CUST-WP-0057`)  
+**Updated:** 2026-07-09
 
 ---
 
@@ -15,6 +15,22 @@ domain-specific coordination models.
 
 ---
 
+## Ecosystem position
+
+`hub-core` is the **library layer** in the three-repo hub stack:
+
+| Repo | Role |
+| --- | --- |
+| `hub-core` | Shared Python package — this repo |
+| `state-hub` | Dev coordination host (primary consumer) |
+| `core-hub` | Production framework (`/api/v2`; adopts hub-core utils) |
+
+Canon: `/home/worsch/the-custodian/docs/hub-ecosystem-architecture.md`
+
+**Naming:** `hub-core` = core *primitives* (library). `core-hub` = core *framework* (service). Do not conflate them.
+
+---
+
 ## Why it exists
 
 Custodian and helix_forge ecosystems need more than one hub-shaped service: