Net::ReadTimeout: Net::ReadTimeout with #<TCPSocket:(closed)> (Net::ReadTimeout)

## Error

```
Net::ReadTimeout with # (Net::ReadTimeout)
```

## Stack trace

```
net/protocol.rb:229 in rbuf_fill
net/protocol.rb:199 in readuntil
net/protocol.rb:209 in readline
net/http/response.rb:158 in Net::HTTPResponse.read_status_line
net/http/response.rb:147 in Net::HTTPResponse.read_new
net/http.rb:2414 in block in Net::HTTP#transport_request
net/http.rb:2405 in catch
net/http.rb:2405 in transport_request
net/http.rb:2378 in request
skylight/probes/net_http.rb:26 in block in Skylight::Probes::NetHTTP::Instrumentation#request
```

## Tracking Details
- **Project**: exercism-rails
- **Sentry**: [Net::ReadTimeout: Net::ReadTimeout with # (Net::ReadTimeout)](https://thalamus-ai.sentry.io/issues/143090982/)
- **Culprit**: SPI::SolutionImageDataController#show
- **First seen:** Aug 26, 2026

Start by inspecting SPI::SolutionImageDataController#show and the listed Net::HTTP stack trace, including the request instrumentation in skylight/probes/net_http.rb. Determine which outbound request is timing out and how this path is expected to behave; done requires a verified fix or regression coverage, but the issue does not name a test or implementation file.

Written by the indexing model from the issue text.