Refactor user management: Extract IUserService and UserService, consolidate user registration, authentication, and profile management. Fix memory leaks in ApiClient, enhance connection management, and improve error handling in AuthController and UsersController. Update IRC command handling to utilize IUserService for user operations.

src/EchoHub.Server/Auth/JwtTokenService.cs

@@ -2,6 +2,7 @@ using System.IdentityModel.Tokens.Jwt;
 using System.Security.Claims;
 using System.Security.Cryptography;
 using System.Text;
+using EchoHub.Core.DTOs;
 using EchoHub.Core.Models;
 using Microsoft.IdentityModel.Tokens;
 
@@ -51,6 +52,31 @@ public class JwtTokenService
         return (new JwtSecurityTokenHandler().WriteToken(token), expiresAt);
     }
 
+    public (string Token, DateTimeOffset ExpiresAt) GenerateAccessToken(UserProfileDto profile)
+    {
+        var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_secret));
+        var credentials = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
+        var expiresAt = DateTimeOffset.UtcNow.Add(AccessTokenLifetime);
+
+        Claim[] claims =
+        [
+            new(JwtRegisteredClaimNames.Sub, profile.Id.ToString()),
+            new("username", profile.Username),
+            new("display_name", profile.DisplayName ?? profile.Username),
+            new("role", profile.Role.ToString()),
+            new(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
+        ];
+
+        var token = new JwtSecurityToken(
+            issuer: _issuer,
+            audience: _audience,
+            claims: claims,
+            expires: expiresAt.UtcDateTime,
+            signingCredentials: credentials);
+
+        return (new JwtSecurityTokenHandler().WriteToken(token), expiresAt);
+    }
+
     public static string GenerateRefreshToken()
     {
         var randomBytes = new byte[64];