refactor(tui): remove unused plugin theme registration (#52992)

packages/tui/src/theme/index.ts

@@ -7,7 +7,6 @@ export { DEFAULT_THEMES, type Theme, type ThemeV1Json } from "./v1"
 
 export type ThemeDocumentSource = Record<string, unknown>
 
-const pluginThemes: Record<string, ThemeDocumentSource> = {}
 let customThemes: Record<string, ThemeDocumentSource> = {}
 let systemTheme: ThemeDocumentSource | undefined
 const listeners = new Set<(themes: Record<string, ThemeDocumentSource>) => void>()
@@ -25,11 +24,10 @@ export function getOpenCodeTheme() {
 }
 
 function listThemes(): Record<string, ThemeDocumentSource> {
-  // Priority: defaults < plugin installs < custom files < generated system.
+  // Priority: defaults < custom files < generated system.
   const themes: Record<string, ThemeDocumentSource> = {
     ...DEFAULT_THEMES,
     opencode: getOpenCodeTheme(),
-    ...pluginThemes,
     ...customThemes,
   }
   return {
@@ -84,27 +82,6 @@ export function hasTheme(name: string) {
   return allThemes()[name] !== undefined
 }
 
-export function addTheme(name: string, theme: unknown) {
-  if (!name) return false
-  if (!isThemeSource(theme)) return false
-  if (hasTheme(name)) return false
-  pluginThemes[name] = theme
-  syncThemes()
-  return true
-}
-
-export function upsertTheme(name: string, theme: unknown) {
-  if (!name) return false
-  if (!isThemeSource(theme)) return false
-  if (customThemes[name] !== undefined) {
-    customThemes[name] = theme
-  } else {
-    pluginThemes[name] = theme
-  }
-  syncThemes()
-  return true
-}
-
 export function resolveTheme(theme: ThemeV1Json, mode: "dark" | "light"): Theme {
   const resolved = resolveThemeColors(theme, mode)
   return {