Fetch PR body inside checker

Authored-By: Codex (GPT-5) <noreply@openai.com>

check.sh

@@ -7,11 +7,12 @@ set -euo pipefail
 BRANCH="${HEAD_BRANCH:-}"
 TITLE="${PR_TITLE:-}"
 AUTHOR="${PR_AUTHOR:-}"
-BODY="${PR_BODY:-}"
 BASE="${BASE_SHA:-}"
 HEAD="${HEAD_SHA:-}"
 SERVER_URL="${GITEA_SERVER_URL:-}"
 TOKEN="${GITEA_TOKEN:-}"
+REPOSITORY="${GITEA_REPOSITORY:-}"
+PR_NUMBER="${GITEA_PR_NUMBER:-}"
 
 # Break-glass: dfritz is exempt from all naming checks.
 if [ "${AUTHOR}" = "dfritz" ]; then
@@ -26,8 +27,19 @@ BRANCH_BUG=""
 # Gitea's renderer is the visibility contract. Validate its output instead of
 # maintaining a second Markdown parser in this action.
 RENDERED_BODY=""
-if [ -z "${SERVER_URL}" ] || [ -z "${TOKEN}" ]; then
-  echo "FAIL[check-naming]: server-url and token are required to render the PR body"
+BODY=""
+if [ -z "${SERVER_URL}" ] || [ -z "${TOKEN}" ] ||
+  ! printf '%s' "${REPOSITORY}" | grep -qE '^[[:alnum:]_.-]+/[[:alnum:]_.-]+$' ||
+  ! printf '%s' "${PR_NUMBER}" | grep -qE '^[1-9][0-9]*$'; then
+  echo "FAIL[check-naming]: server-url, token, repository, and PR number are required to load the PR body"
+  FAILED=1
+elif ! BODY=$(curl --fail --silent --show-error \
+  --connect-timeout 5 \
+  --max-time 15 \
+  --header "Authorization: token ${TOKEN}" \
+  "${SERVER_URL%/}/api/v1/repos/${REPOSITORY}/pulls/${PR_NUMBER}" |
+  jq -er '.body | if type == "string" then . else error("body is not a string") end'); then
+  echo "FAIL[check-naming]: Gitea could not load the PR body"
   FAILED=1
 elif ! RENDERED_BODY=$(printf '%s' "${BODY}" |
   jq -Rs '{Text: ., Mode: "gfm"}' |