Complete REUSE-WP-0003: registry CLI, docs alignment, and coverage

Align INTENT.md with delivered layout, add CapabilityRegistryConcept guide,
extend schema with promotion_history, ship reuse-surface validate/query/export
CLI, register three more helix_forge capabilities, and refresh SCOPE and gap
analysis to reflect A3 tooling and D5/A3/C4/R2 self-assessment.

pyproject.toml

@@ -0,0 +1,21 @@
+[build-system]
+requires = ["setuptools>=68"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "reuse-surface"
+version = "0.1.0"
+description = "Capability registry tooling for reuse-surface"
+readme = "README.md"
+requires-python = ">=3.11"
+dependencies = [
+  "jsonschema>=4.0",
+  "pyyaml>=6.0",
+]
+
+[project.scripts]
+reuse-surface = "reuse_surface.cli:main"
+
+[tool.setuptools.packages.find]
+where = ["."]
+include = ["reuse_surface*"]