fix(server): defer validation error body change

packages/opencode/src/server/routes/instance/httpapi/middleware/schema-error.ts

@@ -1,21 +0,0 @@
-import { Effect } from "effect"
-import { HttpServerResponse } from "effect/unstable/http"
-import { HttpApiMiddleware } from "effect/unstable/httpapi"
-
-export class SchemaErrorMiddleware extends HttpApiMiddleware.Service<SchemaErrorMiddleware>()(
-  "@opencode/ExperimentalHttpApiSchemaError",
-) {}
-
-export const schemaErrorLayer = HttpApiMiddleware.layerSchemaErrorTransform(SchemaErrorMiddleware, (error) => {
-  if (error.kind === "Body") return Effect.fail(error)
-  return Effect.succeed(
-    HttpServerResponse.jsonUnsafe(
-      {
-        data: {},
-        errors: [{ kind: error.kind, message: error.cause.message }],
-        success: false,
-      },
-      { status: 400 },
-    ),
-  )
-})