Use 'Changes since last build (SHA)' format in release notes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: scouzi1966

.github/workflows/nightly.yml

@@ -97,11 +97,9 @@ jobs:
         - **Commit:** ${SHORT_SHA}
         - **Date:** ${BUILD_DATE}
         - **Version:** ${VERSION}
-        - **Changes since:** \`${PREV_SHA}\`
-
         > This is an unstable development build. For the latest stable release, use \`brew install scouzi1966/afm/afm\`.
 
-        ### Changes since \`${PREV_SHA}\`
+        ### Changes since last build (\`${PREV_SHA}\`)
         ${CHANGELOG}
 
         ### Install / Upgrade via Homebrew

Scripts/publish-next.sh

@@ -162,11 +162,9 @@ Nightly build from \`main\` branch.
 - **Commit:** ${SHORT_SHA}
 - **Date:** ${DATE}
 - **Version:** ${VERSION}
-- **Changes since:** \`${PREV_SHA:-first build}\`
-
 > This is an unstable development build. For the latest stable release, use \`brew install scouzi1966/afm/afm\`.
 
-### Changes since \`${PREV_SHA:-first build}\`
+### Changes since last build (\`${PREV_SHA:-first build}\`)
 ${CHANGELOG}
 
 ### Install / Upgrade via Homebrew