Stitch any CI into Tangled

provider/sourcehut: add builds.sr.ht provider #58

Merged j3s.sh
targeting main from j3s.sh/tack:main
Merged opened by and assigned to j3s.sh
targeting main from j3s.sh/tack:main

Submits jobs via GraphQL submit, polls for status, streams per-task logs from /query/log/ (the path that bypasses sourcehut's anti-bot proxy). Workflows opt in via tack.sourcehut.manifest; tack injects TACK_* env vars into the manifest before submission.

Signed-off-by: Jes Olson j3s@c3f.net

apologies if the LLM comments are a little excessive -- i didn't have time to clean them up fully. i reviewed & tested this code, you can see it in action here: https://tangled.org/j3s.sh/testy

and here is an example of a resulting sr.ht build: https://builds.sr.ht/~capsul/job/1749924

Commits 2

sourcehut: add docs
provider/sourcehut: add builds.sr.ht provider