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.

packages/db/src/queries/program/goal.ts

@@ -106,6 +106,8 @@ export async function listAssignmentsForReminderScan(): Promise<
     organizationSiteName: string | null;
     organizationCustomDomain: string | null;
     organizationIsCustomDomainVerified: boolean | null;
+    organizationAvatarUrl: string | null;
+    organizationTheme: string | null;
   }>
 > {
   try {
@@ -120,7 +122,9 @@ export async function listAssignmentsForReminderScan(): Promise<
         organizationName: schema.organization.name,
         organizationSiteName: schema.organization.siteName,
         organizationCustomDomain: schema.organization.customDomain,
-        organizationIsCustomDomainVerified: schema.organization.isCustomDomainVerified
+        organizationIsCustomDomainVerified: schema.organization.isCustomDomainVerified,
+        organizationAvatarUrl: schema.organization.avatarUrl,
+        organizationTheme: schema.organization.theme
       })
       .from(schema.programGoalAssignment)
       .innerJoin(schema.programMember, eq(schema.programGoalAssignment.programMemberId, schema.programMember.id))
@@ -146,7 +150,9 @@ export async function listAssignmentsForReminderScan(): Promise<
         organizationName: row.organizationName,
         organizationSiteName: row.organizationSiteName,
         organizationCustomDomain: row.organizationCustomDomain,
-        organizationIsCustomDomainVerified: row.organizationIsCustomDomainVerified
+        organizationIsCustomDomainVerified: row.organizationIsCustomDomainVerified,
+        organizationAvatarUrl: row.organizationAvatarUrl,
+        organizationTheme: row.organizationTheme
       }));
   } catch (error) {
     console.error('listAssignmentsForReminderScan error:', error);