feat(casan): add native plugin facade

packaging/levels.json

@@ -7,9 +7,12 @@
       "level": 1,
       "package_names": ["casan-core", "casan-harness"],
       "status": "implemented",
-      "summary": "Minimal H1-H7 production runtime: security/action gates, evidence pack, audit, cost/telemetry, policy/config defaults, adapters, lightweight CLI, three-dimensional commercial readiness, and a zero-dependency single-project Local Assurance Viewer with H1-H7, H6, history and on-demand export. Source-only tests and Platform helpers are excluded.",
+      "summary": "Minimal H1-H7 production runtime: security/action gates, evidence pack, audit, cost/telemetry, policy/config defaults, adapters, lightweight CLI, native Codex/Claude operator facade, three-dimensional commercial readiness, and a zero-dependency single-project Local Assurance Viewer with H1-H7, H6, history and on-demand export. Source-only tests and Platform helpers are excluded.",
       "target_users": ["governance-harness-only projects", "BJT initial adoption", "CI gate usage"],
       "includes": [
+        ".codex-plugin",
+        ".claude-plugin",
+        "skills",
         "packages/casan-harness",
         "bin/casan",
         "install.sh",