🔧 refactor: Add and use PrincipalType Enum

- Replaced string literals for principal types ('user', 'group', 'public') with the new PrincipalType enum across various models, services, and tests for improved type safety and consistency.
- Updated permission handling in multiple files to utilize the PrincipalType enum, enhancing maintainability and reducing potential errors.
- Ensured all relevant tests reflect these changes to maintain coverage and functionality.

api/server/controllers/PermissionsController.js

@@ -4,7 +4,7 @@
 
 const mongoose = require('mongoose');
 const { logger } = require('@librechat/data-schemas');
-const { ResourceType } = require('librechat-data-provider');
+const { ResourceType, PrincipalType } = require('librechat-data-provider');
 const {
   bulkUpdateResourcePermissions,
   ensureGroupPrincipalExists,
@@ -235,14 +235,14 @@ const getResourcePermissions = async (req, res) => {
 
     // Process aggregation results
     for (const result of results) {
-      if (result.principalType === 'public') {
+      if (result.principalType === PrincipalType.PUBLIC) {
         publicPermission = {
           public: true,
           publicAccessRoleId: result.accessRoleId,
         };
-      } else if (result.principalType === 'user' && result.userInfo) {
+      } else if (result.principalType === PrincipalType.USER && result.userInfo) {
         principals.push({
-          type: 'user',
+          type: PrincipalType.USER,
           id: result.userInfo._id.toString(),
           name: result.userInfo.name || result.userInfo.username,
           email: result.userInfo.email,
@@ -251,9 +251,9 @@ const getResourcePermissions = async (req, res) => {
           idOnTheSource: result.userInfo.idOnTheSource || result.userInfo._id.toString(),
           accessRoleId: result.accessRoleId,
         });
-      } else if (result.principalType === 'group' && result.groupInfo) {
+      } else if (result.principalType === PrincipalType.GROUP && result.groupInfo) {
         principals.push({
-          type: 'group',
+          type: PrincipalType.GROUP,
           id: result.groupInfo._id.toString(),
           name: result.groupInfo.name,
           email: result.groupInfo.email,

api/server/controllers/agents/v1.js

@@ -9,9 +9,10 @@ const {
   FileSources,
   ResourceType,
   AccessRoleIds,
+  PrincipalType,
   EToolResources,
-  actionDelimiter,
   PermissionBits,
+  actionDelimiter,
   removeNullishValues,
 } = require('librechat-data-provider');
 const {
@@ -80,7 +81,7 @@ const createAgentHandler = async (req, res) => {
     // Automatically grant owner permissions to the creator
     try {
       await grantPermission({
-        principalType: 'user',
+        principalType: PrincipalType.USER,
         principalId: userId,
         resourceType: ResourceType.AGENT,
         resourceId: agent._id,
@@ -346,7 +347,7 @@ const duplicateAgentHandler = async (req, res) => {
     // Automatically grant owner permissions to the duplicator
     try {
       await grantPermission({
-        principalType: 'user',
+        principalType: PrincipalType.USER,
         principalId: userId,
         resourceType: ResourceType.AGENT,
         resourceId: newAgent._id,