migration to typescript

docs/api-docs/ER/ERD_v3_improved.txt

@@ -49,6 +49,7 @@ Table user_profiles {
   last_name varchar [not null]
   phone varchar
   avatar_url varchar
+  birth_date datetime 
   created_at datetime [not null, default: `now()`]
   updated_at datetime
   updated_by int [ref: > users.id]
@@ -126,6 +127,29 @@ Table course_instructors {
   }
 }
 
+Table course_approvals {
+  id int [pk, increment]
+  course_id int [not null, ref: > courses.id]
+  submitted_by int [not null, ref: > users.id, note: 'instructor who submitted']
+  reviewed_by int [ref: > users.id, note: 'admin who reviewed']
+  action varchar [not null, note: 'ENUM: SUBMITTED | APPROVED | REJECTED']
+  previous_status varchar [not null, note: 'status before this action']
+  new_status varchar [not null, note: 'status after this action']
+  comment text [note: 'admin comment or rejection reason']
+  created_at datetime [not null, default: `now()`]
+  
+  Note: 'Tracks complete approval workflow history'
+  
+  indexes {
+    course_id
+    submitted_by
+    reviewed_by
+    action
+    created_at
+    (course_id, created_at)
+  }
+}
+
 Table chapters {
   id int [pk, increment]
   course_id int [not null, ref: > courses.id]
@@ -505,3 +529,6 @@ Table withdrawal_requests {
 //    - enrollments: CASCADE (delete with user/course)
 //    - announcements: CASCADE (delete with course)
 //    - quiz_attempts: CASCADE (delete with user)
+
+
+Ref: "certificates"."issued_at" < "certificates"."enrollment_id"