Replaces {{BUILD_VAR_*}} placeholders in all text files of the calling
repo's checkout with Gitea Actions build/commit/branch info before the
docker build step runs. Language-agnostic (plain text substitution),
runs unconditionally, no-op when no placeholders are present.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01VVTCJvvJmS4fCSrm5wxwVo
