Fix Sortify 4.8.3 REST release body verification

[Lycidias93]

Root cause

The REST publisher reaches draft creation, but the prior exact-body check rendered .body through gh api --jq. CLI string rendering appends an output newline, so byte-level cmp can fail even when GitHub stored the exact Markdown body.

Fix

• compare the JSON .body string directly against the release-notes file via jq --rawfile;
• add non-sensitive stage markers for tag, draft, body, asset, publish and public-hash phases;
• keep target, tag, asset bytes/hash, release notes, build gates, cleanup boundary and stable publication boundary unchanged.

Stable metadata remains 4.8.2 until the public asset hash is verified.