Use wrapper script for label operations in issue triage (#968)

* Use wrapper script for label operations in issue triage

Updates /label-issue command and examples to use a dedicated
edit-issue-labels.sh script for label operations instead of raw
gh issue edit. The script validates labels against the repo's existing
labels before applying them. Also tightens gh search permission to
gh search issues.

* Show multiple --add-label flags in label-issue example

scripts/edit-issue-labels.sh

@@ -0,0 +1,87 @@
+#!/usr/bin/env bash
+#
+# Edits labels on a GitHub issue.
+# Usage: ./scripts/edit-issue-labels.sh --issue 123 --add-label bug --add-label needs-triage --remove-label untriaged
+#
+
+set -euo pipefail
+
+ISSUE=""
+ADD_LABELS=()
+REMOVE_LABELS=()
+
+# Parse arguments
+while [[ $# -gt 0 ]]; do
+  case $1 in
+    --issue)
+      ISSUE="$2"
+      shift 2
+      ;;
+    --add-label)
+      ADD_LABELS+=("$2")
+      shift 2
+      ;;
+    --remove-label)
+      REMOVE_LABELS+=("$2")
+      shift 2
+      ;;
+    *)
+      exit 1
+      ;;
+  esac
+done
+
+# Validate issue number
+if [[ -z "$ISSUE" ]]; then
+  exit 1
+fi
+
+if ! [[ "$ISSUE" =~ ^[0-9]+$ ]]; then
+  exit 1
+fi
+
+if [[ ${#ADD_LABELS[@]} -eq 0 && ${#REMOVE_LABELS[@]} -eq 0 ]]; then
+  exit 1
+fi
+
+# Fetch valid labels from the repo
+VALID_LABELS=$(gh label list --limit 500 --json name --jq '.[].name')
+
+# Filter to only labels that exist in the repo
+FILTERED_ADD=()
+for label in "${ADD_LABELS[@]}"; do
+  if echo "$VALID_LABELS" | grep -qxF "$label"; then
+    FILTERED_ADD+=("$label")
+  fi
+done
+
+FILTERED_REMOVE=()
+for label in "${REMOVE_LABELS[@]}"; do
+  if echo "$VALID_LABELS" | grep -qxF "$label"; then
+    FILTERED_REMOVE+=("$label")
+  fi
+done
+
+if [[ ${#FILTERED_ADD[@]} -eq 0 && ${#FILTERED_REMOVE[@]} -eq 0 ]]; then
+  exit 0
+fi
+
+# Build gh command arguments
+GH_ARGS=("issue" "edit" "$ISSUE")
+
+for label in "${FILTERED_ADD[@]}"; do
+  GH_ARGS+=("--add-label" "$label")
+done
+
+for label in "${FILTERED_REMOVE[@]}"; do
+  GH_ARGS+=("--remove-label" "$label")
+done
+
+gh "${GH_ARGS[@]}"
+
+if [[ ${#FILTERED_ADD[@]} -gt 0 ]]; then
+  echo "Added: ${FILTERED_ADD[*]}"
+fi
+if [[ ${#FILTERED_REMOVE[@]} -gt 0 ]]; then
+  echo "Removed: ${FILTERED_REMOVE[*]}"
+fi