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.

.forgejo/workflows/ci-smoke.yaml

@@ -1,5 +1,4 @@
-# Canonical CI smoke template (tier 1 routing drill).
-# Copy to: .forgejo/workflows/ci-smoke.yaml in consumer repos.
+# CI smoke — package tests prove hub-core library health on push.
 name: CI Smoke
 
 on:
@@ -20,10 +19,26 @@ jobs:
           echo "runner=${RUNNER_NAME:-unknown}"
           uname -a
 
-  container-smoke:
-    runs-on: ubuntu-latest
+  pytest-smoke:
+    runs-on: self-hosted
     steps:
-      - name: Routing probe (container label)
+      - name: Run hub-core pytest
         run: |
           set -eu
-          echo "container-smoke ok for ${GITHUB_REPOSITORY:-unknown}"
+          REF="${GITHUB_SHA:-main}"
+          SHORT="${REF:0:7}"
+          ROOT="${HOME}/ci-hub-core-${SHORT}"
+          rm -rf "${ROOT}"
+          mkdir -p "${ROOT}"
+          wget -qO /tmp/hub-core.tar.gz \
+            "https://forgejo.coulomb.social/${GITHUB_REPOSITORY}/archive/${SHORT}.tar.gz"
+          tar xzf /tmp/hub-core.tar.gz -C "${ROOT}" --strip-components=1
+          cd "${ROOT}"
+          if ! command -v uv >/dev/null 2>&1; then
+            pip install --user uv
+            export PATH="${HOME}/.local/bin:${PATH}"
+          fi
+          uv sync
+          uv run python -c "import hub_core; print(hub_core.__version__)"
+          uv run python -m pytest -q
+          echo "hub-core pytest smoke ok @ ${SHORT}"