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

apps/api/src/routes/course/course.ts

@@ -25,7 +25,7 @@ import {
   getCourseAnalytics,
   getCourseProgress,
   updateCourse
-} from '@api/services/course/course';
+} from '@cio/core/services/course/course';
 import { assertCertificateDownloadAllowed, evaluateCourseCertification } from '@api/services/course/completion';
 import { getCourseTags, replaceCourseTags } from '@api/services/tag';
 
@@ -62,7 +62,7 @@ import { presignRouter } from '@api/routes/course/presign';
 import { assertMcpAutomationUsageAllowed, recordMcpAutomationUsage } from '@api/services/organization/automation-usage';
 import { sectionRouter } from '@api/routes/course/section';
 import { submissionRouter } from '@api/routes/course/submission';
-import { updateCourseLandingPageService } from '@api/services/course/landing-page';
+import { updateCourseLandingPageService } from '@cio/core/services/course/landing-page';
 import { zValidator } from '@hono/zod-validator';
 
 function slugifyForFilename(value: string): string {