fix: broadcast S3DownloadFinished to correct user

The event was broadcasting to the first user in the team instead of
the actual user who triggered the download. This caused the download
message to never hide for other team members.

- Pass userId in S3DownloadFinished event data
- Use the specific userId from event data for broadcasting
- Remove unused User model import
- Ensures broadcast reaches the correct user's private channel

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/Livewire/Project/Database/Import.php

@@ -401,6 +401,7 @@ EOD;
 
             // Execute download commands
             $activity = remote_process($commands, $this->server, ignore_errors: false, callEventOnFinish: 'S3DownloadFinished', callEventData: [
+                'userId' => Auth::id(),
                 'downloadPath' => $downloadPath,
                 'containerName' => $containerName,
                 'serverId' => $this->server->id,