✉️ fix: email address encoding in verification link (#3085)

Related to #3084

Implements URL encoding for email addresses in verification links and decodes them upon verification.

- **Encode email addresses** in `sendVerificationEmail` and `resendVerificationEmail` functions using `encodeURIComponent` to ensure special characters like `+` are correctly handled in the verification link.
- **Decode email addresses** in the `verifyEmail` function using `decodeURIComponent` to accurately retrieve and validate the email address from the verification link against the database.


---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/danny-avila/LibreChat/issues/3084?shareId=9c32df30-4156-4082-a3eb-fff54eaba5b3).

api/server/services/AuthService.js

@@ -62,7 +62,7 @@ const sendVerificationEmail = async (user) => {
   let verifyToken = crypto.randomBytes(32).toString('hex');
   const hash = bcrypt.hashSync(verifyToken, 10);
 
-  const verificationLink = `${domains.client}/verify?token=${verifyToken}&email=${user.email}`;
+  const verificationLink = `${domains.client}/verify?token=${verifyToken}&email=${encodeURIComponent(user.email)}`;
   await sendEmail({
     email: user.email,
     subject: 'Verify your email',
@@ -91,7 +91,7 @@ const sendVerificationEmail = async (user) => {
  */
 const verifyEmail = async (req) => {
   const { email, token } = req.body;
-  let emailVerificationData = await Token.findOne({ email });
+  let emailVerificationData = await Token.findOne({ email: decodeURIComponent(email) });
 
   if (!emailVerificationData) {
     logger.warn(`[verifyEmail] [No email verification data found] [Email: ${email}]`);
@@ -363,7 +363,7 @@ const resendVerificationEmail = async (req) => {
     let verifyToken = crypto.randomBytes(32).toString('hex');
     const hash = bcrypt.hashSync(verifyToken, 10);
 
-    const verificationLink = `${domains.client}/verify?token=${verifyToken}&email=${user.email}`;
+    const verificationLink = `${domains.client}/verify?token=${verifyToken}&email=${encodeURIComponent(user.email)}`;
 
     await sendEmail({
       email: user.email,