feat(remotion): theme system + CharacterJourney pilot template

- src/scenes/themes.ts: 6 curated themes (the cohesion rail) — pick one, then
  tweak the 4 brand colors; every block derives its shades so a theme re-skins
  the whole video coherently (verified: same journey rendered in warm-editorial
  vs berry-pop by overriding only the 4 colors).
- src/scenes/presets.ts: CHARACTER_JOURNEY — the pilot template's scene list
  ("Idea → struggle → tool → win", 7 beats) as a FlexStory preset.
- briefs/character-journey.md: the filled Template Spec from the guided brief.
- Root.tsx: register CharacterJourney per aspect (FlexStory + the preset).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/remotion/src/Root.tsx

@@ -5,6 +5,7 @@ import { Three3DTest } from "./compositions/Three3DTest";
 import { AssetSheet } from "./compositions/AssetSheet";
 import { StoryScenes, STORY_SCENES_DURATION } from "./compositions/StoryScenes";
 import { FlexStory, flexStorySchema, flexStoryDefaults, calcFlexStoryMetadata } from "./compositions/FlexStory";
+import { CHARACTER_JOURNEY } from "./scenes/presets";
 import {
   IlluminatedCircles,
   illuminatedCirclesSchema,
@@ -156,6 +157,22 @@ export const RemotionRoot: React.FC = () => {
         />
       ))}
 
+      {/* CharacterJourney — pilot template: a curated FlexStory scene list (theme + story). */}
+      {ASPECTS.map((a) => (
+        <Composition
+          key={`CharacterJourney-${a.id}`}
+          id={`CharacterJourney-${a.id}`}
+          component={FlexStory}
+          durationInFrames={26 * FPS}
+          fps={FPS}
+          width={a.width}
+          height={a.height}
+          schema={flexStorySchema}
+          defaultProps={CHARACTER_JOURNEY}
+          calculateMetadata={calcFlexStoryMetadata}
+        />
+      ))}
+
       {/* Branded templates — each registered in all three aspects. A template may
           supply a dedicated component per aspect (componentsByAspect) when its
           design differs structurally; otherwise the shared `component` adapts