fix(ci): remove || true guards from jq pipelines in audit-force-merge.sh

Silent-failure regression from 8c343e3a. The || true guards on jq
pipelines masked parse errors and allowed empty strings to propagate
into the force-merge audit event (e.g. missing title, merge_sha, or
merged_by). With set -euo pipefail already in place, jq failures now
propagate as hard errors — the correct behavior.

Use jq's // operator for graceful defaults instead:
  MERGE_SHA=$(jq -r '.merge_commit_sha // empty')   # exits 5 on missing field
  MERGED_BY=$(jq -r '.merged_by.login // "unknown"')  # exits 5 on missing field

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

.gitea/scripts/audit-force-merge.sh

@@ -49,11 +49,16 @@ if [ "$MERGED" != "true" ]; then
   exit 0
 fi
 
-MERGE_SHA=$(echo "$PR" | jq -r '.merge_commit_sha // empty') || true
-MERGED_BY=$(echo "$PR" | jq -r '.merged_by.login // "unknown"') || true
-TITLE=$(echo "$PR" | jq -r '.title // ""') || true
-BASE_BRANCH=$(echo "$PR" | jq -r '.base.ref // "main"') || true
-HEAD_SHA=$(echo "$PR" | jq -r '.head.sha // empty') || true
+# NOTE: no || true — with set -euo pipefail, jq parse failures (e.g. field
+# missing from API response) propagate as hard errors. Use jq's // operator
+# for graceful defaults instead of bash || true guards. This was re-added by
+# 8c343e3a ("fix(gitea): add || true guards to jq pipelines") — reverted
+# here because the guards mask silent failures that hide malformed API responses.
+MERGE_SHA=$(echo "$PR" | jq -r '.merge_commit_sha // empty')
+MERGED_BY=$(echo "$PR" | jq -r '.merged_by.login // "unknown"')
+TITLE=$(echo "$PR" | jq -r '.title // ""')
+BASE_BRANCH=$(echo "$PR" | jq -r '.base.ref // "main"')
+HEAD_SHA=$(echo "$PR" | jq -r '.head.sha // empty')
 
 if [ -z "$MERGE_SHA" ]; then
   echo "::warning::PR #${PR_NUMBER} merged=true but no merge_commit_sha — cannot evaluate force-merge."
@@ -75,7 +80,7 @@ STATUS=$(curl -sS -H "$AUTH" \
 declare -A CHECK_STATE
 while IFS=$'\t' read -r ctx state; do
   [ -n "$ctx" ] && CHECK_STATE[$ctx]="$state"
-done < <(echo "$STATUS" | jq -r '.statuses // [] | .[] | "\(.context)\t\(.status)"') || true
+done < <(echo "$STATUS" | jq -r '.statuses // [] | .[] | "\(.context)\t\(.status)"')
 
 # 4. For each required check, was it green at merge? YAML block scalars
 #    (`|`) leave a trailing newline; skip blank/whitespace-only lines.
@@ -97,7 +102,10 @@ fi
 
 # 5. Emit structured audit event.
 NOW=$(date -u +%Y-%m-%dT%H:%M:%SZ)
-FAILED_JSON=$(printf '%s\n' "${FAILED_CHECKS[@]}" | jq -R . | jq -s .) || true
+# jq -R (raw input) converts each line to a JSON string; jq -s wraps into array.
+# If FAILED_CHECKS is unexpectedly empty (shouldn't happen — we exit above),
+# this produces []. No || true needed.
+FAILED_JSON=$(printf '%s\n' "${FAILED_CHECKS[@]}" | jq -R . | jq -s .)
 
 # Print as a single-line JSON so Vector's parse_json transform can pick
 # it up cleanly from docker_logs.