Migrate UI cancel error to tagged error (#27112)

packages/opencode/src/cli/error.ts

@@ -78,8 +78,8 @@ export function FormatError(input: unknown) {
     ].join("\n")
   }
 
-  // UICancelledError: void (no data)
-  if (NamedError.hasName(input, "UICancelledError")) {
+  // UICancelledError: user cancelled an interactive CLI prompt
+  if (isTaggedError(input, "UICancelledError") || NamedError.hasName(input, "UICancelledError")) {
     return ""
   }
 }

packages/opencode/src/cli/ui.ts

@@ -1,5 +1,4 @@
 import { EOL } from "os"
-import { NamedError } from "@opencode-ai/core/util/error"
 import { Schema } from "effect"
 import { logo as glyphs } from "./logo"
 
@@ -10,7 +9,7 @@ const wordmark = [
   `▀▀▀▀ █▀▀▀ ▀▀▀▀ ▀  ▀ ▀▀▀▀ ▀▀▀▀ ▀▀▀▀ ▀▀▀▀`,
 ]
 
-export const CancelledError = NamedError.create("UICancelledError", Schema.optional(Schema.Void))
+export class CancelledError extends Schema.TaggedErrorClass<CancelledError>()("UICancelledError", {}) {}
 
 export const Style = {
   TEXT_HIGHLIGHT: "\x1b[96m",