feat(oc-plugin): add MACP ACP runtime backend

plugins/macp/openclaw.plugin.json

@@ -0,0 +1,28 @@
+{
+  "id": "macp",
+  "name": "MACP Runtime",
+  "description": "Registers the macp ACP runtime backend and dispatches Pi turns through the MACP Pi runner.",
+  "configSchema": {
+    "type": "object",
+    "additionalProperties": false,
+    "properties": {
+      "defaultModel": {
+        "type": "string",
+        "description": "Default Pi model in provider/model format. Defaults to openai/gpt-5-mini."
+      },
+      "systemPrompt": {
+        "type": "string",
+        "description": "Optional system prompt prepended to each Pi turn."
+      },
+      "timeoutMs": {
+        "type": "number",
+        "minimum": 1,
+        "description": "Maximum turn runtime in milliseconds. Defaults to 300000."
+      },
+      "logDir": {
+        "type": "string",
+        "description": "Directory for Pi runtime logs. Defaults to the plugin state dir."
+      }
+    }
+  }
+}