* fix(inbounds): allow negative subSortIndex for subscription order
Preserve explicitly set negative indices so primary inbounds can sort
ahead of the default without renumbering peers; keep 0/omitted → 1.
* fix(inbounds): gofumpt model.go and trim subSortIndex comments
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Co-authored-by: mrchatam <287639636+mrchatam@users.noreply.github.com>