feat: add Latchshot page capture blueprint

[BaiqingL]

Summary

• add a typed blueprint that renders a public page as PNG, JPEG, or PDF through Latchshot
• stream the binary response directly into Kestra internal storage with io.kestra.plugin.core.http.Download
• expose the stored artifact as a flow-level FILE output
• document the exact secret, inputs, outputs, storage boundary, restrictions, and API links

I maintain Latchshot and am contributing this blueprint directly. Latchshot is not affiliated with Kestra.

Safety and data boundaries

• public HTTP/HTTPS pages only; private, loopback, credential-bearing, and non-web-port targets are rejected
• no cookies, page credentials, injected scripts, or payment actions
• the response is direct binary data, not a temporary third-party URL; Kestra owns artifact retention after download
• the linked Free-key request does not start a paid plan

Validation

• Kestra 1.3.28 native flow validation: passed with no warnings after removing only the catalog-specific extend block
• bounded live Kestra execution: SUCCESS, HTTP 200 image/png, 16,323 bytes, valid PNG signature, stored and downloaded from a kestra:/// URI
• SHA-256 of the stored runtime artifact: 62dd2b7f0cb8469b892d8d6f7b1cbbbea3befc989d7e96f84ce5d956fafc9de6
• repository tag validator equivalent: all 483 flows parsed and passed allowed-tag/count rules
• Prettier, YAML parsing, metadata/filename checks, secret scan, and git diff --check: passed
• the one-render .invalid QA credential was revoked immediately; the run is not customer or revenue evidence

Checklist

• id matches the hyphen-case filename and namespace is set
• task is fully defined and described
• extend includes title, rich description, <=160-character meta description, tags, ee, and demo
• prerequisites, secret purpose, inputs, outputs, pitfalls, and links are documented
• no hardcoded credential; the flow uses secret("LATCHSHOT_API_KEY")

[MilosPaunovic]

Hey @wrussell1999 @aj-emerich could you give this a look once you get a chance please?

[wrussell1999]

I like what this flow does however for an ideal blueprint, it should contain multiple tasks.

Can you extend the usage here so there's tasks downstream that do something with this image? Maybe something that could pass it to an LLM to describe it and then send the result to you via email or another platform? Open to your suggestions though!

I tested it and it works.