Add scheduled repository cleanup workflow

manifest.schema.json

@@ -55,6 +55,30 @@
         }
       }
     },
+    "cleanupAutomation": {
+      "type": "object",
+      "required": ["workflow", "target", "schedule", "checks", "destructive"],
+      "properties": {
+        "workflow": {
+          "type": "string"
+        },
+        "target": {
+          "type": "string"
+        },
+        "schedule": {
+          "type": "string"
+        },
+        "checks": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        },
+        "destructive": {
+          "type": "boolean"
+        }
+      }
+    },
     "workflows": {
       "type": "object",
       "required": ["newRepository", "existingProject", "quickstart"],