feat(studio): reflect account-voice / series-scope field split

Robot-author edit form and detail drop positioning/target_readers (now
series-level); persona + styles stay (routed to the account profile via the
admin API). Series detail shows positioning/target_readers. Types updated;
admin API types regenerated.

src/api/types.ts

@@ -152,9 +152,8 @@ export interface StudioRobotAuthor {
   avatar?: string | null
   category_id: string
   subtopic_id: string | null
+  /** Account-level voice — stored on the shared profile, flattened into the author. */
   persona: string | null
-  positioning: string | null
-  target_readers: string | null
   article_style: Record<string, unknown> | null
   image_style: Record<string, unknown> | null
   publishing_rules: Record<string, unknown> | null
@@ -173,6 +172,9 @@ export interface StudioSeries {
   subtopic_id: string | null
   robot_author_id: string
   goal: string | null
+  /** Series-level angle/audience (moved off the author). */
+  positioning: string | null
+  target_readers: string | null
   reader_journey: string | null
   target_article_count: number | null
   planned_articles: unknown[] | null