- Rename _manifest_util.py → manifest_util.py (module isn't private)
- Rename _as_json_object → as_json_object, _parse_git_upstream → parse_git_upstream,
_parse_git_gate_config → parse_git_gate_config,
_validate_unique_git_names → validate_unique_git_names,
_validate_egress_routes → validate_egress_routes (none are private at
module boundary — underscore prefix was a carry-over from the old
monolithic manifest.py where everything lived in one namespace)
- Move _is_ip_literal → util.is_ip_literal (generic, belongs in the
top-level util module)
- Update all import sites across manifest_*.py, manifest_extends.py,
manifest_schema.py; existing callers of manifest.py are unaffected
All 867 unit tests pass.