refactor(opencode): replace Bun shell in core flows (#16286)

packages/opencode/src/project/vcs.ts

@@ -1,11 +1,11 @@
 import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
-import { $ } from "bun"
 import path from "path"
 import z from "zod"
 import { Log } from "@/util/log"
 import { Instance } from "./instance"
 import { FileWatcher } from "@/file/watcher"
+import { git } from "@/util/git"
 
 const log = Log.create({ service: "vcs" })
 
@@ -29,13 +29,13 @@ export namespace Vcs {
   export type Info = z.infer<typeof Info>
 
   async function currentBranch() {
-    return $`git rev-parse --abbrev-ref HEAD`
-      .quiet()
-      .nothrow()
-      .cwd(Instance.worktree)
-      .text()
-      .then((x) => x.trim())
-      .catch(() => undefined)
+    const result = await git(["rev-parse", "--abbrev-ref", "HEAD"], {
+      cwd: Instance.worktree,
+    })
+    if (result.exitCode !== 0) return
+    const text = result.text().trim()
+    if (!text) return
+    return text
   }
 
   const state = Instance.state(