feat(input): provide convenience constructors for image input segments

[activadee]

Summary

• Add convenience constructors to create image input segments from URLs and in-memory bytes, with automatic temp-file handling and cleanup.

Changes

• feat(input):
  • Add URLImageSegment to download an image, validate Content-Type, and store in a temp file.
  • Add BytesImageSegment to write provided bytes to a temp file with an appropriate extension.
  • Extend InputSegment with an internal cleanup hook; update normalizeInput to collect and expose a cleanup function.
• fix(thread):
  • Ensure temporary image files are always cleaned up in streamed runs (on error and on completion).
• test(input):
  • Add tests for URLImageSegment, BytesImageSegment, and cleanup behavior.
• docs(readme):
  • Rename section and document the new constructors with examples.

Notes

• Backwards compatible: existing TextSegment and LocalImageSegment usage remains unchanged.
• Temporary files created by the helpers are cleaned automatically after each run.

closes #12

[github-actions]

URLImageSegment currently slurps the entire response into memory via io.ReadAll. Because the helper is intended for arbitrary remote URLs, a large or malicious server response can easily exhaust memory and make the process unstable. Please stream the download to disk (or at least cap the bytes you buffer up front for type sniffing) instead of reading the full body into RAM.

[github-actions]

Codex Review Summary

Recommendation: ✅ Ready to merge – no blocking issues detected.

Summary:
No issues found. The new streaming download path enforces the 8 MiB cap safely using an io.LimitedReader, verifies the Content-Type before writing, and streams into the temp file without buffering the full payload in memory. The validator cleanup logic removes partial files when the size check fails, and the added test covers the size-limit branch. I’m confident in the change after tracing the limit/cleanup flow and ensuring existing nil-body safeguards remain intact.

Inline findings:

• No inline findings.

Generated at 2025-11-06T19:43:29.925Z.