fix(tui): show bootstrap errors instead of {} to trace (#4779)

Co-authored-by: Github Action <action@github.com>

packages/opencode/src/cli/error.ts

@@ -38,3 +38,18 @@ export function FormatError(input: unknown) {
 
   if (UI.CancelledError.isInstance(input)) return ""
 }
+
+export function FormatUnknownError(input: unknown): string {
+  if (input instanceof Error) {
+    return input.stack ?? `${input.name}: ${input.message}`
+  }
+
+  if (typeof input === "object" && input !== null) {
+    try {
+      const json = JSON.stringify(input, null, 2)
+      if (json && json !== "{}") return json
+    } catch {}
+  }
+
+  return String(input)
+}