feat: add @opencode-ai/util package with utility functions

packages/util/src/fn.ts

@@ -0,0 +1,11 @@
+import { z } from "zod"
+
+export function fn<T extends z.ZodType, Result>(schema: T, cb: (input: z.infer<T>) => Result) {
+  const result = (input: z.infer<T>) => {
+    const parsed = schema.parse(input)
+    return cb(parsed)
+  }
+  result.force = (input: z.infer<T>) => cb(input)
+  result.schema = schema
+  return result
+}

packages/util/src/iife.ts

@@ -0,0 +1,3 @@
+export function iife<T>(fn: () => T) {
+  return fn()
+}

packages/util/src/lazy.ts

@@ -0,0 +1,11 @@
+export function lazy<T>(fn: () => T) {
+  let value: T | undefined
+  let loaded = false
+
+  return (): T => {
+    if (loaded) return value as T
+    loaded = true
+    value = fn()
+    return value as T
+  }
+}