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/storybook/src/templates/org-landing-page/course-landing-page.stories.svelte

@@ -0,0 +1,89 @@
+<script module>
+  import { defineMeta } from '@storybook/addon-svelte-csf';
+  import {
+    MinimalCourseLanding,
+    BoldCourseLanding,
+    ClassicCourseLanding,
+    SaasCourseLanding,
+    TechCourseLanding,
+    StudioCourseLanding,
+    CorporateCourseLanding,
+    TerminalCourseLanding,
+    EditorialCourseLanding,
+    VibrantCourseLanding,
+    mockCourseLandingPageProps as mockProps
+  } from '@cio/ui/custom/org-landing-page';
+
+  const { Story } = defineMeta({
+    title: 'Templates/Course Landing Page',
+    parameters: {
+      layout: 'fullscreen'
+    },
+    tags: ['autodocs']
+  });
+</script>
+
+<Story name="Minimal">
+  <MinimalCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Bold">
+  <BoldCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Classic">
+  <ClassicCourseLanding {...mockProps} />
+</Story>
+
+<Story name="SaaS">
+  <SaasCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Tech">
+  <TechCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Studio">
+  <StudioCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Corporate">
+  <CorporateCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Terminal">
+  <TerminalCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Editorial">
+  <EditorialCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Vibrant">
+  <VibrantCourseLanding {...mockProps} />
+</Story>
+
+<Story name="Gallery · all themes">
+  <div class="ui:flex ui:flex-col">
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Minimal</div>
+    <MinimalCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Bold</div>
+    <BoldCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Classic</div>
+    <ClassicCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">SaaS</div>
+    <SaasCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Tech</div>
+    <TechCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Studio</div>
+    <StudioCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Corporate</div>
+    <CorporateCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Terminal</div>
+    <TerminalCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Editorial</div>
+    <EditorialCourseLanding {...mockProps} />
+    <div class="ui:sticky ui:top-0 ui:z-50 ui:bg-black/85 ui:text-white ui:text-xs ui:px-4 ui:py-2">Vibrant</div>
+    <VibrantCourseLanding {...mockProps} />
+  </div>
+</Story>