feat: HLS streaming, transcripts, agent course generation & landing-page course previews (#663)

New features:
- HLS video encoding/streaming (hls routes, hls-encoder) and a media
  transcripts pipeline (transcripts route + media-transcript queries)
- AI assistant chat vs. run model: agent-course-generation worker/queue,
  run-monitor pane, chat-changes card, content ask-ai bar
- Per-theme course-page previews across org landing-page themes (bold,
  classic, corporate, editorial, etc.) with a shared course token/component set
- View-as-student mode and login-link / link-invite invite flows

Refactor:
- Extract packages/core consolidating config (env, storage, dashboard-url),
  services and utils previously duplicated under apps/api/src/config
- Remove legacy agent service modules (chat-tools, chat-context,
  context-window, document, fetch-url, lesson-content)
- Relax Cross-Origin-Resource-Policy to allow cross-origin media embedding
- Add format script to tenant-router so turbo run format covers it

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

@@ -104,6 +104,8 @@ export async function listAssignmentsForReminderScan(): Promise<
     programName: string;
     organizationName: string;
     organizationSiteName: string | null;
+    organizationCustomDomain: string | null;
+    organizationIsCustomDomainVerified: boolean | null;
   }>
 > {
   try {
@@ -116,7 +118,9 @@ export async function listAssignmentsForReminderScan(): Promise<
         programId: schema.program.id,
         programName: schema.program.name,
         organizationName: schema.organization.name,
-        organizationSiteName: schema.organization.siteName
+        organizationSiteName: schema.organization.siteName,
+        organizationCustomDomain: schema.organization.customDomain,
+        organizationIsCustomDomainVerified: schema.organization.isCustomDomainVerified
       })
       .from(schema.programGoalAssignment)
       .innerJoin(schema.programMember, eq(schema.programGoalAssignment.programMemberId, schema.programMember.id))
@@ -140,7 +144,9 @@ export async function listAssignmentsForReminderScan(): Promise<
         programId: row.programId,
         programName: row.programName,
         organizationName: row.organizationName,
-        organizationSiteName: row.organizationSiteName
+        organizationSiteName: row.organizationSiteName,
+        organizationCustomDomain: row.organizationCustomDomain,
+        organizationIsCustomDomainVerified: row.organizationIsCustomDomainVerified
       }));
   } catch (error) {
     console.error('listAssignmentsForReminderScan error:', error);