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/services/agent/chat-history.ts

@@ -12,7 +12,13 @@ import {
 
 const MAX_PERSISTED_TOOL_OUTPUT_CHARS = 2000;
 const DROPPED_PART_TYPES = new Set(['step-start', 'reasoning']);
-const TOOLS_WITH_FULL_OUTPUT = new Set(['generate_course_plan', 'ask_template_questions', 'fetch_documentation_url']);
+const TOOLS_WITH_FULL_OUTPUT = new Set([
+  'generate_course_plan',
+  'ask_template_questions',
+  'fetch_documentation_url',
+  'get_course_structure',
+  'get_exercise_details'
+]);
 
 function isRecord(value: unknown): value is Record<string, unknown> {
   return value !== null && typeof value === 'object' && !Array.isArray(value);