fix lsp diagnostic accurancy

packages/opencode/src/util/timeout.ts

@@ -0,0 +1,14 @@
+export function withTimeout<T>(promise: Promise<T>, ms: number): Promise<T> {
+  let timeout: NodeJS.Timeout
+  return Promise.race([
+    promise.then((result) => {
+      clearTimeout(timeout)
+      return result
+    }),
+    new Promise<never>((_, reject) => {
+      timeout = setTimeout(() => {
+        reject(new Error(`Operation timed out after ${ms}ms`))
+      }, ms)
+    }),
+  ])
+}