refactor(db): streamline model imports and remove unused model exports

- Removed the export of models from the database connection module to simplify the structure.
- Updated various files to import models directly from the new centralized models module.
- Ensured consistency across the codebase by replacing mongoose model references with the new import paths.

api/server/index.js

@@ -9,8 +9,9 @@ const passport = require('passport');
 const mongoSanitize = require('express-mongo-sanitize');
 const fs = require('fs');
 const cookieParser = require('cookie-parser');
+const { connectDb, indexSync } = require('~/db');
+
 const { jwtLogin, passportLogin } = require('~/strategies');
-const { connectDb, indexSync, getModels } = require('db');
 const { isEnabled } = require('~/server/utils');
 const { ldapLogin } = require('~/strategies');
 const { logger } = require('~/config');