Add aiven plugin (#4821)

Driver: dir-plugin-add-official

.claude-plugin/marketplace.json

@@ -121,6 +121,20 @@
       },
       "homepage": "https://www.airwallex.com/docs"
     },
+    {
+      "name": "aiven",
+      "description": "Easily deploy managed PostgreSQL (pg), Kafka, OpenSearch, Clickhouse and other databases, streaming and apps. Free tier available, up and running in minutes.",
+      "author": {
+        "name": "Aiven"
+      },
+      "category": "database",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/aiven/aiven-ai-plugins.git",
+        "sha": "634f41d6852957cb9280e9245f2ea6f74645b4f1"
+      },
+      "homepage": "https://aiven.io"
+    },
     {
       "name": "alloydb",
       "description": "Create, connect, and interact with an AlloyDB for PostgreSQL database and data.",