Implement SAND-WP-0003: validation meta-framework extraction

Port e2e-framework schema, runner, and reporter into wise-validator with
sand-boxer CLI integration, validate run CLI, unit tests, registry capability,
and operator docs.

tests/fixtures/minimal_repo/docker-compose.yml

@@ -0,0 +1,5 @@
+services:
+  web:
+    image: docker.io/library/nginx:alpine
+    ports:
+      - "127.0.0.1:8080:80"