feat(email): use HTML templates for all transactional emails

- Update org invite, password reset, email verification, and account activation emails to use HTML templates
- Update MFA deadline reminder and suspension notifications to use HTML templates
- Add html_body parameter to _send_email_async for rich email content

gatehouse_app/api/v1/auth/core.py

@@ -9,6 +9,7 @@ from gatehouse_app.schemas.auth_schema import RegisterSchema, LoginSchema
 from gatehouse_app.services.auth_service import AuthService
 from gatehouse_app.services.mfa_policy_service import MfaPolicyService
 from gatehouse_app.services.notification_service import NotificationService
+from gatehouse_app.services.email_templates import build_email_verification_html
 from gatehouse_app.utils.decorators import login_required
 from gatehouse_app.utils.constants import AuditAction
 from gatehouse_app.exceptions.auth_exceptions import InvalidCredentialsError
@@ -32,14 +33,17 @@ def register():
             verify_token = EmailVerificationToken.generate(user_id=user.id)
             app_url = current_app.config.get("APP_URL", "http://localhost:8080")
             verify_link = f"{app_url}/verify-email?token={verify_token.token}"
-            subject = "Verify your Secuird email address"
-            body = (
-                f"Hi {user.full_name or user.email},\n\n"
-                f"Welcome to Secuird! Please verify your email address by clicking the link below (valid for 24 hours):\n"
-                f"{verify_link}\n\n"
-                f"Secuird Security Team"
+            email_body = build_email_verification_html(
+                user_name=user.full_name or user.email,
+                verify_link=verify_link,
+                expiry_hours=24,
+            )
+            NotificationService._send_email_async(
+                to_address=user.email,
+                subject="Verify your Secuird email address",
+                body=f"Verify your Secuird email: {verify_link}",
+                html_body=email_body,
             )
-            NotificationService._send_email_async(to_address=user.email, subject=subject, body=body)
         except Exception as exc:
             logging.getLogger(__name__).warning(f"Failed to send verification email on register: {exc}")
 

gatehouse_app/api/v1/auth/password.py

@@ -6,6 +6,11 @@ from gatehouse_app.extensions import limiter
 from gatehouse_app.utils.response import api_response
 from gatehouse_app.services.auth_service import AuthService
 from gatehouse_app.services.notification_service import NotificationService
+from gatehouse_app.services.email_templates import (
+    build_password_reset_html,
+    build_email_verification_html,
+    build_account_activation_html,
+)
 
 _logger = logging.getLogger(__name__)
 
@@ -27,17 +32,16 @@ def forgot_password():
             reset_token = PasswordResetToken.generate(user_id=user.id)
             app_url = current_app.config.get("APP_URL", "http://localhost:8080")
             reset_link = f"{app_url}/reset-password?token={reset_token.token}"
+            email_body = build_password_reset_html(
+                user_name=user.full_name or user.email,
+                reset_link=reset_link,
+                expiry_hours=2,
+            )
             NotificationService._send_email_async(
                 to_address=user.email,
                 subject="Reset your Secuird password",
-                body=(
-                    f"Hi {user.full_name or user.email},\n\n"
-                    f"You requested a password reset for your Secuird account.\n\n"
-                    f"Click the link below to reset your password (valid for 2 hours):\n"
-                    f"{reset_link}\n\n"
-                    f"If you did not request this, you can safely ignore this email.\n\n"
-                    f"Secuird Security Team"
-                ),
+                body=f"Reset your Secuird password: {reset_link}",
+                html_body=email_body,
             )
             _logger.info(f"Password reset token generated for user {user.id}")
         except Exception as exc:
@@ -129,15 +133,16 @@ def resend_verification():
             verify_token = EmailVerificationToken.generate(user_id=user.id)
             app_url = current_app.config.get("APP_URL", "http://localhost:8080")
             verify_link = f"{app_url}/verify-email?token={verify_token.token}"
+            email_body = build_email_verification_html(
+                user_name=user.full_name or user.email,
+                verify_link=verify_link,
+                expiry_hours=24,
+            )
             NotificationService._send_email_async(
                 to_address=user.email,
                 subject="Verify your Secuird email address",
-                body=(
-                    f"Hi {user.full_name or user.email},\n\n"
-                    f"Please verify your email address by clicking the link below (valid for 24 hours):\n"
-                    f"{verify_link}\n\n"
-                    f"Secuird Security Team"
-                ),
+                body=f"Verify your Secuird email: {verify_link}",
+                html_body=email_body,
             )
             _logger.info(f"Verification email sent for user {user.id}")
         except Exception as exc:
@@ -200,16 +205,15 @@ def resend_activation():
 
             app_url = current_app.config.get("APP_URL", current_app.config.get("FRONTEND_URL", "http://localhost:8080"))
             activate_link = f"{app_url}/activate?code={code}"
+            email_body = build_account_activation_html(
+                user_name=user.full_name or user.email,
+                activation_link=activate_link,
+            )
             NotificationService._send_email_async(
                 to_address=user.email,
                 subject="Activate your Secuird account",
-                body=(
-                    f"Hi {user.full_name or user.email},\n\n"
-                    f"Please activate your Secuird account by clicking the link below:\n"
-                    f"{activate_link}\n\n"
-                    f"If you did not create an account, you can safely ignore this email.\n\n"
-                    f"Secuird Security Team"
-                ),
+                body=f"Activate your Secuird account: {activate_link}",
+                html_body=email_body,
             )
             _logger.info(f"Activation email re-sent to {user.id}")
         except Exception as exc: