Complete WP-0006 through WP-0009: registry expansion, catalog, graph, tests

Register six new capabilities (12 total), add searchable catalog UI and graph
explorer, introduce pytest suite with CI fail-on-warnings, and close gap
analysis priorities 13 and 16. WP-0010 remains backlog for network federation.

pyproject.toml

@@ -13,6 +13,11 @@ dependencies = [
   "pyyaml>=6.0",
 ]
 
+[project.optional-dependencies]
+dev = [
+  "pytest>=8.0",
+]
+
 [project.scripts]
 reuse-surface = "reuse_surface.cli:main"