feat(engine): Architect agent + cross-scene StoryState coherence

Add a dedicated Architect LLM call at session start that expands the terse
world/style prompt into a persistent story bible (logline, genre, second-
person protagonist, cast, engineered opening hook). The bible seeds a
StoryState the Writer reads and patches every scene, carried + merged
across cuts (applyStoryStatePatch) so the story keeps a spine from beat
one instead of jumping between scenes.

- prompts: inject web-novel / short-drama / galgame craft into Writer +
  Architect; Writer emits storyStatePatch to update the running bible
- director: parallelize voice + non-entry portraits with the Painter
  (only entry-beat portraits block paint) to offset Architect latency
- architect: chat/parse guarded so a malformed response never aborts start
- types: StoryState / StoryStatePatch; required on Start/SceneResponse

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitignore

@@ -20,3 +20,5 @@ npm-debug.log*
 pnpm-debug.log*
 
 repomix-output.xml
+
+users.md