feat: Implement instructor course management pages and service for listing, creating, viewing, and editing courses.

frontend_management/pages/instructor/courses/index.vue

@@ -236,7 +236,7 @@ const fetchCourses = async () => {
 const getStatusColor = (status: string) => {
   const colors: Record<string, string> = {
     APPROVED: 'green',
-    PENDING: 'yellow',
+    PENDING: 'orange',
     DRAFT: 'grey',
     REJECTED: 'red'
   };
@@ -275,12 +275,23 @@ const confirmDelete = (course: CourseResponse) => {
     message: `คุณต้องการลบหลักสูตร "${course.title.th}" หรือไม่?`,
     cancel: true,
     persistent: true
-  }).onOk(() => {
-    $q.notify({
-      type: 'positive',
-      message: 'ลบหลักสูตรสำเร็จ',
-      position: 'top'
-    });
+  }).onOk(async () => {
+    try {
+      await instructorService.deleteCourse(course.id);
+      $q.notify({
+        type: 'positive',
+        message: 'ลบหลักสูตรสำเร็จ',
+        position: 'top'
+      });
+      // Refresh list
+      fetchCourses();
+    } catch (error) {
+      $q.notify({
+        type: 'negative',
+        message: 'ไม่สามารถลบหลักสูตรได้',
+        position: 'top'
+      });
+    }
   });
 };