重构会话消息处理和显示逻辑

src/lib/pending-prompt-text.ts

@@ -1,18 +0,0 @@
-const pendingPromptTextByContextKey = new Map<string, string>()
-
-export function setPendingPromptText(contextKey: string, text: string): void {
-  const normalized = text.trim()
-  if (!normalized) {
-    pendingPromptTextByContextKey.delete(contextKey)
-    return
-  }
-  pendingPromptTextByContextKey.set(contextKey, normalized)
-}
-
-export function getPendingPromptText(contextKey: string): string | null {
-  return pendingPromptTextByContextKey.get(contextKey) ?? null
-}
-
-export function clearPendingPromptText(contextKey: string): void {
-  pendingPromptTextByContextKey.delete(contextKey)
-}