fix: Bug详情图片放大关闭不影响抽屉 + 仅修复人可操作

1. Lightbox 点击关闭时 stopPropagation，不会冒泡关闭 drawer
   - 点击背景关闭图片
   - 新增右上角 X 关闭按钮
   - 点击图片本身不触发关闭

2. 仅当前修复人（assigneeId）可操作 Bug：
   - 只有当前用户 === bug.assigneeId 时显示状态流转按钮和转交按钮
   - 其他人查看时显示提示"仅修复人可操作"

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/components/bug/BugDetailDrawer.tsx

@@ -103,7 +103,7 @@ export function BugDetailDrawer({ bugId, onClose }: Props) {
               <span className="text-[11px] text-[var(--ink-muted)]">{bug.priority}</span>
             </div>
 
-            {nextStatuses.length > 0 && !showResolutionInput && (
+            {nextStatuses.length > 0 && !showResolutionInput && operator === bug.assigneeId && (
               <div className="flex items-center gap-2 pt-1 flex-wrap">
                 <ChevronRight className="h-3.5 w-3.5 text-[var(--ink-muted)]" />
                 {nextStatuses.map((s) => (
@@ -118,6 +118,9 @@ export function BugDetailDrawer({ bugId, onClose }: Props) {
                 )}
               </div>
             )}
+            {nextStatuses.length > 0 && !showResolutionInput && operator !== bug.assigneeId && (
+              <div className="text-[11px] text-[var(--ink-muted)] pt-1">当前修复人为 {bug.assigneeId}，仅修复人可操作</div>
+            )}
 
             {showResolutionInput && (
               <div className="space-y-2 pt-1">
@@ -209,8 +212,11 @@ export function BugDetailDrawer({ bugId, onClose }: Props) {
 
       {/* Lightbox */}
       {lightboxSrc && (
-        <div className="fixed inset-0 z-[70] flex items-center justify-center bg-black/70" onClick={() => setLightboxSrc(null)}>
+        <div className="fixed inset-0 z-[70] flex items-center justify-center bg-black/70" onClick={(e) => { e.stopPropagation(); setLightboxSrc(null); }}>
-          <img src={lightboxSrc} alt="大图预览" className="max-h-[85vh] max-w-[85vw] rounded-lg shadow-2xl" />
+          <img src={lightboxSrc} alt="大图预览" className="max-h-[85vh] max-w-[85vw] rounded-lg shadow-2xl" onClick={(e) => e.stopPropagation()} />
+          <button onClick={(e) => { e.stopPropagation(); setLightboxSrc(null); }} className="absolute top-4 right-4 h-8 w-8 flex items-center justify-center rounded-full bg-white/20 hover:bg-white/40 text-white">
+            <X className="h-5 w-5" />
+          </button>
         </div>
       )}
     </div>