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/api/src/routes/internal/compliance.ts

@@ -3,9 +3,19 @@ import { runProgramGoalEvaluationSweep, runProgramGoalReminderScan } from '@api/
 
 import { Hono } from '@api/utils/hono';
 import { apiKeyMiddleware } from '@api/middlewares/api-key';
+import { enqueueSessionReminderScan } from '@cio/jobs';
 import { handleError } from '@api/utils/errors';
 
 export const internalComplianceRouter = new Hono()
+  .post('/send-session-reminders', apiKeyMiddleware, async (c) => {
+    try {
+      const jobId = await enqueueSessionReminderScan();
+
+      return c.json({ success: true, data: { jobId: jobId ?? null } }, 200);
+    } catch (error) {
+      return handleError(c, error, 'Failed to enqueue session reminder scan');
+    }
+  })
   .post('/check-expiry', apiKeyMiddleware, async (c) => {
     try {
       const data = await runComplianceExpiryCheck();