Previous approaches using temp files or env vars failed in Gitea runner.
Python now runs git commands directly via subprocess, reads stdout,
and builds the JSON payload — no intermediate files or shell escaping.
Bare git repo has no HEAD; git log without --all showed nothing.
Now uses /var/www/atom-nexst (full checkout with proper HEAD).
Also adds debug output and handles first-release edge case.
Shallow clone (depth 1) only has one commit, so git log was empty.
Now generates changelog from the bare repo before cloning, and uses
Python to build the JSON payload for proper multiline escaping.
openhands