test(FN-2712): add runtime e2e and integration coverage

- Add OpenClaw runtime end-to-end tests covering execution flow and runtime contract behavior
- Add OpenClaw integration tests to validate plugin/runtime wiring in engine scenarios
- Add Paperclip runtime end-to-end and integration suites for equivalent cross-runtime coverage
- Update Hermes, OpenClaw, and Paperclip manifest descriptions for consistent runtime metadata

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

@@ -8,7 +8,7 @@
   "runtime": {
     "runtimeId": "openclaw",
     "name": "OpenClaw Runtime",
-    "description": "OpenClaw-backed AI session using the user's configured pi provider and model",
+    "description": "OpenClaw-backed AI session using the local OpenClaw gateway",
     "version": "0.1.0"
   }
 }