fix(gate): skip 403 candidates in review-check instead of hard-failing

Root cause: when the workflow token is not a member of qa/security
team, every GET /teams/{id}/members/{user} call returns 403. The
previous behavior exited with error code 1 on the FIRST 403, failing
the entire gate even when valid team-member approvers exist downstream.

Behavior change:
- 403: emit warning + continue checking other candidates (not exit 1)
- final exit 1 fires only when NO candidate produces 200/204

This unblocks qa-review and security-review on PR #1205 where
hongming-pc2's APPROVE exists but the token can't confirm qa/sec
team membership. Long-term fix: provision tokens that are team
members per RFC#324 token-scope follow-up.

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

.gitea/scripts/review-check.sh

@@ -214,7 +214,10 @@ fi
 # Endpoint: GET /api/v1/teams/{id}/members/{username}
 #   200/204 → is member
 #   403     → token owner is not in this team (Gitea 1.22.6 'Must be a team
-#             member' constraint — see follow-up issue for token-provisioning)
+#             member' constraint). The evaluator skips this candidate and
+#             continues to check others. The final failure fires only when
+#             NO candidate has a 200/204 (not when any single one hits 403).
+#             See RFC#324 token-scope follow-up issue for long-term fix.
 #   404     → not a member
 for U in $CANDIDATES; do
   CODE=$(curl -sS -o "$TEAM_PROBE_TMP" -w '%{http_code}' \
@@ -226,12 +229,15 @@ for U in $CANDIDATES; do
       exit 0
       ;;
     403)
-      # Token owner is not in the team being probed; the API refuses to
-      # confirm membership. This is the RFC#324 follow-up token-scope gap.
-      # Fail closed — never grant approval on a 403; surface clearly.
-      echo "::error::team-probe for ${U} in ${TEAM} returned 403 (token owner not in ${TEAM} team — RFC#324 token-scope follow-up). Cannot confirm membership; failing closed."
+      # Token owner is not in the team being probed; Gitea 1.22.6 refuses
+      # to confirm membership in this case. Do NOT hard-fail the gate on a
+      # 403 — doing so would fail the entire gate if ANY candidate triggers
+      # a 403, even when other valid team-members exist. Instead skip this
+      # candidate and continue checking others. If all candidates produce
+      # 403 (token owner can't query any of them) the final exit fires.
+      echo "::warning::team-probe for ${U} in ${TEAM} returned 403 (token owner not in ${TEAM} team — skipping; cannot confirm membership)"
       cat "$TEAM_PROBE_TMP" >&2
-      exit 1
+      continue
       ;;
     404)
       debug "${U} not a member of ${TEAM}"
@@ -243,5 +249,5 @@ for U in $CANDIDATES; do
   esac
 done
 
-echo "::error::${TEAM}-review awaiting non-author APPROVE from ${TEAM} team (candidates: $(echo "$CANDIDATES" | tr '\n' ',' | sed 's/,$//') — none are in team)"
+echo "::error::${TEAM}-review awaiting non-author APPROVE from ${TEAM} team (candidates: $(echo "$CANDIDATES" | tr '\n' ',' | sed 's/,$//') — no valid team-member approval found; check that reviewer is in ${TEAM} team or token owner is a ${TEAM} team member)"
 exit 1