feat: live class sessions, CE workflow, and docs (#683)

Adds live-class session scheduling on lessons (join link, date/time,
timezone) with automatic 24h and 1h reminder emails plus a calendar
invite (.ics), a time-change notification with an updated invite, a
teacher-authored welcome email and session invite on enrollment, and a
"Notify students" quiz nudge.

LMS gets an upcoming live-sessions card and Join buttons, plus a
reusable live-session card component (3 states) in @cio/ui with a
Storybook story. The sidebar content tree now reflects sequential
progression locking like the content list, and the course-completion
confetti regression is fixed.

Org-based emails no longer reference ClassroomIO by name. Docs add
live-class, welcome-email, and course-progression guides, expand the
certificates guide (design, signatures, corrected labels), move
plan-required callouts to the top, flatten how-to-guides to the docs
root with redirects, and add screenshots. Includes an add-docs-image
skill.

apps/dashboard/src/lib/features/course/components/lesson/content-navigation-actions.svelte

@@ -14,7 +14,11 @@
   import { ContentType } from '@cio/utils/constants/content';
   import { snackbar } from '$features/ui/snackbar/store';
   import type { CourseContentItem } from '$features/course/utils/types';
-  import { openCourseCompletionModal } from '$features/course/store/course-completion-modal';
+  import {
+    openCourseCompletionModal,
+    updateCourseCompletionModal,
+    closeCourseCompletionModal
+  } from '$features/course/store/course-completion-modal';
   import { updateLessonCompletionInCourseContent } from '$features/course/utils/content-completion';
 
   interface Props {
@@ -135,7 +139,19 @@
         navigableContentItems.every((item) => item.isComplete);
 
       if (allComplete) {
+        const requiredExerciseId = courseApi.course?.certificate?.requiredExerciseId ?? undefined;
         openCourseCompletionModal(courseId);
+
+        const certRes = await courseApi.getCertificationEvaluation(courseId);
+        if (certRes?.data) {
+          if (certRes.data.isNewCompletion) {
+            updateCourseCompletionModal(courseId, 'eligible', certRes.data, requiredExerciseId);
+          } else {
+            updateCourseCompletionModal(courseId, 'not-eligible', certRes.data, requiredExerciseId);
+          }
+        } else {
+          closeCourseCompletionModal();
+        }
       }
     } else {
       snackbar.error('snackbar.lessons.error.try_later');