feat(FN-2347): add experimental OpenClaw runtime plugin scaffold

- Add fusion-plugin-openclaw-runtime workspace package with manifest, runtime metadata, and deferred placeholder factory
- Add unit tests for OpenClaw plugin behavior and PluginRunner runtime discovery compatibility
- Document OpenClaw runtime installation and runtimeHint usage in README, getting-started, and settings reference docs
- Include built dist artifacts for the new plugin and update workspace/lockfile entries

plugins/fusion-plugin-openclaw-runtime/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "rootDir": "src",
+    "types": ["node", "vitest/globals"]
+  },
+  "include": ["src/**/*"]
+}