ci: avoid gh dependency in internal CI

Use the GitHub REST API with curl to fetch PR metadata so the 017 self-hosted runner does not need GitHub CLI installed.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: Zachary-wW

.github/workflows/internal-ci.yml

@@ -77,15 +77,19 @@ jobs:
             exit 1
           fi
 
-          PR_DATA=$(gh pr view "$PR_NUM" --json headRefOid,headRefName --repo "$GITHUB_REPOSITORY")
-          BRANCH=$(printf '%s' "$PR_DATA" | jq -r '.headRefName')
-          HEAD_SHA=$(printf '%s' "$PR_DATA" | jq -r '.headRefOid')
-
           if ! printf '%s' "$PR_NUM" | grep -Eq '^[0-9]+$'; then
             echo "Invalid PR number: $PR_NUM"
             exit 1
           fi
 
+          PR_DATA=$(curl -fsSL \
+            -H "Authorization: Bearer $GH_TOKEN" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            "https://api.github.com/repos/$GITHUB_REPOSITORY/pulls/$PR_NUM")
+          BRANCH=$(printf '%s' "$PR_DATA" | jq -r '.head.ref')
+          HEAD_SHA=$(printf '%s' "$PR_DATA" | jq -r '.head.sha')
+
           SHA7=$(printf '%s' "$HEAD_SHA" | cut -c1-7)
           TIMESTAMP=$(date +%s)
           SAFE_BRANCH=$(printf '%s' "$BRANCH" | sed 's#[^A-Za-z0-9._-]#_#g' | cut -c1-120)