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.

pyproject.toml

@@ -5,6 +5,7 @@ description = "Third-generation production interaction framework for Coulomb / H
 readme = "README.md"
 requires-python = ">=3.12"
 dependencies = [
+  "hub-core",
   "fastapi>=0.115",
   "pydantic>=2.8",
   "sqlalchemy[asyncio]>=2.0",
@@ -25,6 +26,9 @@ dev = [
   "playwright>=1.60.0",
 ]
 
+[tool.uv.sources]
+hub-core = { path = "/home/worsch/hub-core", editable = true }
+
 [tool.pytest.ini_options]
 testpaths = ["tests"]
 pythonpath = ["src"]