feat: add CourseDetailView component with video preview, curriculum, enrollment logic, and i18n support

Frontend-Learner/i18n/locales/en.json

@@ -47,7 +47,8 @@
     "buyNow": "Buy this course",
     "enrollFree": "Enroll for free",
     "loginToEnroll": "Log in to enroll",
-    "minutes": "Minutes"
+    "minutes": "Minutes",
+    "noVideoPreview": "Video preview not available"
   },
   "sidebar": {
     "overview": "Home",

Frontend-Learner/i18n/locales/th.json

@@ -47,7 +47,8 @@
     "buyNow": "ซื้อคอร์สเรียนนี้",
     "enrollFree": "ลงทะเบียนเรียนฟรี",
     "loginToEnroll": "เข้าสู่ระบบเพื่อลงทะเบียน",
-    "minutes": "นาที"
+    "minutes": "นาที",
+    "noVideoPreview": "วิดีโอตัวอย่างยังไม่พร้อมใช้งาน"
   },
   "sidebar": {
     "overview": "หน้าหลัก",