feat: add claude code plugin config (#137)

Co-authored-by: Averi Kitsch <akitsch@google.com>

Author: twishabansal

.claude-plugin/marketplace.json

@@ -0,0 +1,16 @@
+{
+  "name": "cloud-sql-postgresql-marketplace",
+  "owner": {
+    "name": "Google LLC",
+    "email": "data-cloud-ai-integrations@google.com"
+  },
+  "metadata": {
+    "description": "Agent skills for Cloud SQL for PostgreSQL to query, manage, and monitor databases."
+  },
+  "plugins": [
+    {
+      "name": "cloud-sql-postgresql",
+      "source": "./"
+    }
+  ]
+}

.claude-plugin/plugin.json

@@ -0,0 +1,57 @@
+{
+  "name": "cloud-sql-postgresql",
+  "version": "0.3.0",
+  "description": "Create, connect, and interact with a Cloud SQL for PostgreSQL database and data.",
+  "author": {
+    "name": "Google LLC",
+    "email": "data-cloud-ai-integrations@google.com"
+  },
+  "homepage": "https://cloud.google.com/sql",
+  "license": "Apache-2.0",
+  "repository": "https://github.com/gemini-cli-extensions/cloud-sql-postgresql",
+  "skills": "./skills/",
+  "userConfig": {
+    "cloud_sql_postgres_project": {
+      "title": "Project ID",
+      "description": "ID of the Google Cloud project",
+      "type": "string",
+      "sensitive": false
+    },
+    "cloud_sql_postgres_region": {
+      "title": "Region",
+      "description": "Region of the Cloud SQL instance",
+      "type": "string",
+      "sensitive": false
+    },
+    "cloud_sql_postgres_instance": {
+      "title": "Instance Name",
+      "description": "Name of the Cloud SQL instance",
+      "type": "string",
+      "sensitive": false
+    },
+    "cloud_sql_postgres_database": {
+      "title": "Database Name",
+      "description": "Name of the database",
+      "type": "string",
+      "sensitive": false
+    },
+    "cloud_sql_postgres_user": {
+      "title": "Database User",
+      "description": "(Optional) Username of the database user (Default: IAM user)",
+      "type": "string",
+      "sensitive": false
+    },
+    "cloud_sql_postgres_password": {
+      "title": "Database Password",
+      "description": "(Optional) Password of the database user (Default: IAM user)",
+      "type": "string",
+      "sensitive": false
+    },
+    "cloud_sql_postgres_ip_type": {
+      "title": "IP Type",
+      "description": "(Optional) Type of the IP address: PUBLIC, PRIVATE, or PSC (Default: Public)",
+      "type": "string",
+      "sensitive": false
+    }
+  }
+}