refactor(characters): drive shared UI from active character

src/stores/chat/chat-state.ts

@@ -2,7 +2,10 @@ import type { UiMessage } from "@/stores/chat/ui-message";
 import type { PendingChatUnlockKind } from "@/lib/navigation/chat_unlock_session";
 import type { ChatLockType } from "@/data/schemas/chat";
 import type { PendingChatPromotion } from "@/data/storage/navigation";
-import { DEFAULT_CHARACTER_ID } from "@/data/constants/character";
+import {
+  DEFAULT_CHARACTER,
+  DEFAULT_CHARACTER_ID,
+} from "@/data/constants/character";
 import type { ChatPromotionState } from "./helper/promotion";
 
 export type ChatUpgradeReason = "insufficient_credits";
@@ -26,6 +29,7 @@ export interface ChatUnlockPaywallRequest
 
 export interface ChatState {
   characterId: string;
+  emptyChatGreeting: string;
   messages: UiMessage[];
   promotion: ChatPromotionState | null;
   outgoingMessageRevision: number;
@@ -55,9 +59,11 @@ export interface ChatState {
 
 export function createInitialChatState(
   characterId: string = DEFAULT_CHARACTER_ID,
+  emptyChatGreeting: string = DEFAULT_CHARACTER.emptyChatGreeting,
 ): ChatState {
   return {
     characterId,
+    emptyChatGreeting,
     messages: [],
     promotion: null,
     outgoingMessageRevision: 0,