Add PostgreSQL support to MCP Database Server

Updated package.json and package-lock.json to include PostgreSQL dependencies. Enhanced README with PostgreSQL usage instructions and configuration details. Modified index.ts to handle PostgreSQL connection parameters and logging. Added PostgresqlAdapter for database interactions.

src/db/adapter.ts

@@ -53,6 +53,7 @@ export interface DbAdapter {
 // Import adapters using dynamic imports
 import { SqliteAdapter } from './sqlite-adapter.js';
 import { SqlServerAdapter } from './sqlserver-adapter.js';
+import { PostgresqlAdapter } from './postgresql-adapter.js';
 
 /**
  * Factory function to create the appropriate database adapter
@@ -68,6 +69,9 @@ export function createDbAdapter(type: string, connectionInfo: any): DbAdapter {
       }
     case 'sqlserver':
       return new SqlServerAdapter(connectionInfo);
+    case 'postgresql':
+    case 'postgres':
+      return new PostgresqlAdapter(connectionInfo);
     default:
       throw new Error(`Unsupported database type: ${type}`);
   }