fix(uploads): trust HEAD size to prevent quota inflation

The head.size > 0 fallback let a client PUT 0 bytes and register
with an inflated size, debiting quota without storing data. HEAD
on an existing object always returns the true byte count, so trust
it directly — a genuine 0-byte file correctly contributes 0.

Author: waleedlatif1

apps/sim/lib/uploads/contexts/workspace/workspace-file-manager.ts

@@ -305,7 +305,7 @@ export async function registerUploadedWorkspaceFile(params: {
     if (!head) {
       throw new Error('Uploaded object not found in storage')
     }
-    verifiedSize = head.size > 0 ? head.size : size
+    verifiedSize = head.size
   }
 
   const cleanupOrphan = async (reason: string) => {