feat(course): auto-enrol button for paid course join requests (#769)

* feat(course): add auto-enrol flow for paid course join requests

- Extend teacher buy-request email with manual access steps and an
  Auto Enrol this Student button
- Link teachers to the course People page with grantAccess query param
- Add grant-access modal that sends the same org audience invite used
  by the Invite new students flow

Co-authored-by: Rotimi Best <[email protected]>

* fix(i18n): translate grant access modal strings

Replace English placeholders copied into non-en locale files with
proper translations for each supported language.

Co-authored-by: Rotimi Best <[email protected]>

* fix(email): shorten auto-enrol button label per review

Co-authored-by: Rotimi Best <[email protected]>

* fix(email): use American spelling Enroll in auto-enroll CTA

Co-authored-by: Rotimi Best <[email protected]>

* fix(i18n): localize Danish grant-access send invite label

Co-authored-by: Rotimi Best <[email protected]>

---------

Co-authored-by: Rotimi Best <[email protected]>

packages/email/src/emails/teacher-student-buy-request.ts

@@ -11,6 +11,8 @@ export const teacherStudentBuyRequestEmail = defineEmail({
     courseName: z.string().min(1),
     studentEmail: z.string().email(),
     studentFullname: z.string().min(1),
+    courseUrl: z.url(),
+    autoEnrollUrl: z.url(),
     branding: ZEmailBranding
   }),
   render: (fields) => {
@@ -22,6 +24,19 @@ export const teacherStudentBuyRequestEmail = defineEmail({
         Name: ${fields.studentFullname}<br />
         Email: ${fields.studentEmail}
       </p>
+      <p style="font-weight: bold; margin-top: 24px;">How to give this student access</p>
+      <ol style="padding-left: 20px; line-height: 1.6;">
+        <li>Open the course: <a href="${fields.courseUrl}">${fields.courseUrl}</a></li>
+        <li>Click <strong>People</strong> on the sidebar</li>
+        <li>Click <strong>Add</strong></li>
+        <li>Under <strong>Invite new students</strong>, enter <strong>${fields.studentEmail}</strong></li>
+        <li>Click <strong>Invite Students</strong></li>
+      </ol>
+      <p style="font-weight: bold; margin-top: 24px;">Or automatically enroll them</p>
+      <p>Use the button below to open the course and send this student an invite in one step.</p>
+      <div>
+        <a class="button" href="${fields.autoEnrollUrl}">Auto Enroll Student</a>
+      </div>
     `;
 
     return getDefaultTemplate(content, fields.branding);