fix(render): iter 69b — re-indent python -c body inside YAML block scalar
iter 69 broke yaml parsing because the multi-line python -c body had
0-space leading lines, which left the YAML block scalar mid-stream.
Indent each python line to match the heredoc's 6-space base (sed strip
in the shim writer leaves them at correct python indent at runtime).
[AGENT: kael]