feat: integrate PostgreSQL with TypeORM and update app configuration

- Added @nestjs/typeorm and pg dependencies for PostgreSQL support.
- Configured TypeORM in app.module.ts to connect to PostgreSQL using environment variables.
- Enhanced main.ts to log database connection details during bootstrap.
- Removed unused disruption module, controller, service, and demo data.

package.json

@@ -26,10 +26,13 @@
     "@nestjs/core": "^11.0.1",
     "@nestjs/platform-express": "^11.0.1",
     "@nestjs/swagger": "^11.2.0",
+    "@nestjs/typeorm": "^11.0.3",
     "class-transformer": "^0.5.1",
     "class-validator": "^0.14.2",
+    "pg": "^8.22.0",
     "reflect-metadata": "^0.2.2",
-    "rxjs": "^7.8.1"
+    "rxjs": "^7.8.1",
+    "typeorm": "^1.0.0"
   },
   "devDependencies": {
     "@eslint/eslintrc": "^3.2.0",