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/ui/src/custom/org-landing-page/classic/hero.svelte

@@ -8,9 +8,10 @@
 
   interface Props {
     hero: OrgLandingPageProps['hero'];
+    showActions?: boolean;
   }
 
-  let { hero }: Props = $props();
+  let { hero, showActions = true }: Props = $props();
 </script>
 
 <EditableLandingSection sectionKey="hero">
@@ -30,23 +31,25 @@
         {hero.heading}
       </BlurIn>
       <p class="ui:text-lg ui:sm:text-xl ui:text-[var(--landing-bg)]/80 ui:mb-10">{hero.subheading}</p>
-      <div class="ui:flex ui:flex-col ui:sm:flex-row ui:justify-center ui:gap-4">
-        <Button
-          href={hero.primaryAction.href}
-          disabled={hero.primaryAction.disabled ?? false}
-          size="lg"
-          class="ui:px-8 ui:font-semibold"
-        >
-          {hero.primaryAction.label}
-        </Button>
-        {#if hero.secondaryAction}
-          <SecondaryActionButton
-            href={hero.secondaryAction.href}
-            label={hero.secondaryAction.label}
-            variant="classic"
-          />
-        {/if}
-      </div>
+      {#if showActions}
+        <div class="ui:flex ui:flex-col ui:sm:flex-row ui:justify-center ui:gap-4">
+          <Button
+            href={hero.primaryAction.href}
+            disabled={hero.primaryAction.disabled ?? false}
+            size="lg"
+            class="ui:px-8 ui:font-semibold"
+          >
+            {hero.primaryAction.label}
+          </Button>
+          {#if hero.secondaryAction}
+            <SecondaryActionButton
+              href={hero.secondaryAction.href}
+              label={hero.secondaryAction.label}
+              variant="classic"
+            />
+          {/if}
+        </div>
+      {/if}
     </div>
   </section>
 </EditableLandingSection>