refactor(core): consolidate filesystem services (#30447)

packages/opencode/src/util/bom.ts

@@ -1,5 +1,5 @@
 import { Effect } from "effect"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 
 const BOM_CODE = 0xfeff
 const BOM = String.fromCharCode(BOM_CODE)
@@ -15,15 +15,11 @@ export function join(text: string, bom: boolean) {
   return BOM + stripped
 }
 
-export const readFile = Effect.fn("Bom.readFile")(function* (fs: AppFileSystem.Interface, filePath: string) {
+export const readFile = Effect.fn("Bom.readFile")(function* (fs: FSUtil.Interface, filePath: string) {
   return split(new TextDecoder("utf-8", { ignoreBOM: true }).decode(yield* fs.readFile(filePath)))
 })
 
-export const syncFile = Effect.fn("Bom.syncFile")(function* (
-  fs: AppFileSystem.Interface,
-  filePath: string,
-  bom: boolean,
-) {
+export const syncFile = Effect.fn("Bom.syncFile")(function* (fs: FSUtil.Interface, filePath: string, bom: boolean) {
   const current = yield* readFile(fs, filePath)
   if (current.bom === bom) return current.text
   yield* fs.writeWithDirs(filePath, join(current.text, bom))