fix(sdk): handle Windows opencode spawn and shutdown (#20772)

packages/opencode/package.json

@@ -51,7 +51,7 @@
     "@tsconfig/bun": "catalog:",
     "@types/babel__core": "7.20.5",
     "@types/bun": "catalog:",
-    "@types/cross-spawn": "6.0.6",
+    "@types/cross-spawn": "catalog:",
     "@types/mime-types": "3.0.1",
     "@types/npmcli__arborist": "6.3.3",
     "@types/semver": "^7.5.8",
@@ -118,7 +118,7 @@
     "bun-pty": "0.4.8",
     "chokidar": "4.0.3",
     "clipboardy": "4.0.0",
-    "cross-spawn": "^7.0.6",
+    "cross-spawn": "catalog:",
     "decimal.js": "10.5.0",
     "diff": "catalog:",
     "drizzle-orm": "catalog:",

packages/opencode/src/util/process.ts

@@ -144,7 +144,11 @@ export namespace Process {
     throw new RunFailedError(cmd, out.code, out.stdout, out.stderr)
   }
 
+  // Duplicated in `packages/sdk/js/src/process.ts` because the SDK cannot import
+  // `opencode` without creating a cycle. Keep both copies in sync.
   export async function stop(proc: ChildProcess) {
+    if (proc.exitCode !== null || proc.signalCode !== null) return
+
     if (process.platform !== "win32" || !proc.pid) {
       proc.kill()
       return