tui: fix prompt ref initialization to prevent undefined reference errors

packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx

@@ -89,7 +89,7 @@ export function Prompt(props: PromptProps) {
   const fileStyleId = syntax().getStyleId("extmark.file")!
   const agentStyleId = syntax().getStyleId("extmark.agent")!
   const pasteStyleId = syntax().getStyleId("extmark.paste")!
-  let promptPartTypeId: number
+  let promptPartTypeId = 0
 
   sdk.event.on(TuiEvent.PromptAppend.type, (evt) => {
     input.insertText(evt.properties.text)
@@ -310,14 +310,7 @@ export function Prompt(props: PromptProps) {
     ]
   })
 
-  createEffect(() => {
-    if (props.visible !== false) input?.focus()
-    if (props.visible === false) input?.blur()
-  })
-
-  onMount(() => {
-    promptPartTypeId = input.extmarks.registerType("prompt-part")
-    props.ref?.({
+  const ref: PromptRef = {
     get focused() {
       return input.focused
     },
@@ -348,7 +341,11 @@ export function Prompt(props: PromptProps) {
     submit() {
       submit()
     },
-    })
+  }
+
+  createEffect(() => {
+    if (props.visible !== false) input?.focus()
+    if (props.visible === false) input?.blur()
   })
 
   function restoreExtmarksFromParts(parts: PromptInfo["parts"]) {
@@ -920,6 +917,10 @@ export function Prompt(props: PromptProps) {
               }}
               ref={(r: TextareaRenderable) => {
                 input = r
+                if (promptPartTypeId === 0) {
+                  promptPartTypeId = input.extmarks.registerType("prompt-part")
+                }
+                props.ref?.(ref)
                 setTimeout(() => {
                   input.cursorColor = theme.text
                 }, 0)