postgres serves the store seat's verbs, databases and query, and lists its tools (hq ADR 0159)

Named as the seat names them so the runtime finds them by name; the same calls as its own tools.
Its definition now lists its tools, which is what holding a seat with verbs demands at registration.
Merge before the controller declares the verbs on the mesh-store seat.

modules/postgres/module.json

@@ -133,5 +133,11 @@
         "from": "Dockerfile"
       }
     ]
-  }
+  },
+  "tools": [
+    "databases",
+    "query",
+    "postgres_list_databases",
+    "postgres_query"
+  ]
 }

modules/postgres/tools/index.ts

@@ -8,6 +8,32 @@ import { PostgresClient } from "../client.js";
 
 export function getPostgresTools(postgres: PostgresClient): ToolDefinition[] {
   return [
+    // The store seat's verbs (novox/hq ADR 0159), served by this module wherever it holds the seat:
+    // named as the seat names them, so the runtime finds them by name, and answering with the same
+    // calls as this module's own tools below. A holder that is not the store serves nothing here;
+    // the bus admits the seat's subjects only to the holder.
+    {
+      name: "databases",
+      description: "The store seat's verb: every database the store holds, with its on-disk size.",
+      input: {},
+      run: async () => ({ databases: await postgres.listDatabases() }),
+    },
+    {
+      name: "query",
+      description: "The store seat's verb: one read-only statement against one database the store holds.",
+      input: {
+        database: { type: "string", description: "the database to query" },
+        sql: { type: "string", description: "the SELECT (or other read-only) statement" },
+      },
+      run: async (args) => {
+        const database = String(args.database ?? "");
+        const sql = String(args.sql ?? "");
+        if (!database) throw new Error("query: database is required");
+        if (!sql) throw new Error("query: sql is required");
+        const result = await postgres.readOnlyQuery(database, sql);
+        return { database, command: result.command, rows: result.rows };
+      },
+    },
     {
       name: "postgres_list_databases",
       description: "List the databases on the postgres server, with their on-disk size.",