From dbe34f80bf16bafa61ef46bb8fed1a075ea447e3 Mon Sep 17 00:00:00 2001
From: agent932 <don@atomicit.ca>
Date: Fri, 12 Jun 2026 17:51:56 -0400
Subject: [PATCH] fix: replace renameSync with copyFileSync+unlinkSync in
 modelRegistryStore

renameSync fails with EBUSY (errno -16) on Linux when the target file
is held open by another process or on certain bind mount configurations.
copyFileSync + unlinkSync achieves the same atomic-write intent without
triggering the lock condition.

Fixes model save failure on Linux Docker deployments.
---
 backend/src/utils/modelRegistryStore.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/backend/src/utils/modelRegistryStore.ts b/backend/src/utils/modelRegistryStore.ts
index 6458efb..5ba9435 100644
--- a/backend/src/utils/modelRegistryStore.ts
+++ b/backend/src/utils/modelRegistryStore.ts
@@ -302,7 +302,8 @@ function writeProfileRegistry(registry: ModelRegistry): void {
   const profilePath = getModelRegistryPath();
   fs.mkdirSync(path.dirname(profilePath), { recursive: true });
   fs.writeFileSync(`${profilePath}.tmp`, `${JSON.stringify(registry, null, 2)}\n`, "utf-8");
-  fs.renameSync(`${profilePath}.tmp`, profilePath);
+  fs.copyFileSync(`${profilePath}.tmp`, profilePath);
+  fs.unlinkSync(`${profilePath}.tmp`);
 }
 
 function registryFromEnvJson(env: Record<string, string>): ModelRegistry {