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/package.json

@@ -0,0 +1,31 @@
+{
+  "name": "@fusion-plugin-examples/openclaw-runtime",
+  "version": "0.1.0",
+  "type": "module",
+  "description": "OpenClaw runtime plugin for Fusion - experimental placeholder runtime registration",
+  "keywords": [
+    "fusion-plugin",
+    "openclaw",
+    "runtime",
+    "experimental"
+  ],
+  "exports": {
+    ".": {
+      "types": "./src/index.ts",
+      "import": "./dist/index.js"
+    }
+  },
+  "private": true,
+  "scripts": {
+    "build": "tsc",
+    "test": "vitest run --silent=passed-only --reporter=dot"
+  },
+  "dependencies": {
+    "@fusion/plugin-sdk": "workspace:*"
+  },
+  "devDependencies": {
+    "@types/node": "^25.5.2",
+    "typescript": "^5.7.0",
+    "vitest": "^3.2.4"
+  }
+}