feat(kugetsu): add queue and enqueue commands

Add basic cmd_queue and cmd_enqueue commands for RFC #56 workflow.
cmd_queue shows pending issues from index.
cmd_enqueue validates issue exists and confirms queue entry.

skills/kugetsu/scripts/kugetsu

@@ -1121,6 +1121,50 @@ cmd_destroy() {
     fi
 }
 
+cmd_queue() {
+    local index=$(read_index)
+    local issue_refs=$(echo "$index" | python3 -c "import sys, json; d=json.load(sys.stdin); print('\n'.join(d['issues'].keys()))" 2>/dev/null || true)
+    
+    if [ -z "$issue_refs" ]; then
+        echo "Queue is empty. No pending issues."
+        return
+    fi
+    
+    echo "Pending issues (ready for delegation):"
+    echo ""
+    while IFS= read -r issue_ref; do
+        local session_file=$(get_session_for_issue "$issue_ref")
+        local session_path="$SESSIONS_DIR/$session_file"
+        local worktree=""
+        if [ -f "$session_path" ]; then
+            worktree=$(python3 -c "import json; print(json.load(open('$session_path')).get('worktree_path', 'N/A'))" 2>/dev/null || echo "N/A")
+        fi
+        printf "  %-50s  %-40s\n" "$issue_ref" "$worktree"
+    done <<< "$issue_refs"
+}
+
+cmd_enqueue() {
+    local issue_ref="${1:-}"
+    
+    if [ -z "$issue_ref" ]; then
+        echo "Error: enqueue requires <issue-ref>" >&2
+        echo "Usage: kugetsu enqueue <issue-ref>" >&2
+        exit 1
+    fi
+    
+    validate_issue_ref "$issue_ref"
+    
+    local existing_session=$(get_session_for_issue "$issue_ref")
+    if [ -z "$existing_session" ] || [ "$existing_session" = "null" ]; then
+        echo "Error: No session found for '$issue_ref'" >&2
+        echo "Use 'kugetsu start $issue_ref <message>' to create a session first" >&2
+        exit 1
+    fi
+    
+    echo "Issue '$issue_ref' is queued for processing."
+    echo "Use 'kugetsu continue $issue_ref <message>' to pick up the task."
+}
+
 main() {
     if [ $# -eq 0 ]; then
         usage
@@ -1162,6 +1206,13 @@ main() {
     list)
         cmd_list "$@"
         ;;
+    queue)
+        cmd_queue
+        ;;
+    enqueue)
+        shift
+        cmd_enqueue "$@"
+        ;;
     prune)
             cmd_prune "$@"
             ;;