fix: 侧边详情显示产品/项目/版本上下文

所有 Drawer 新增 contextLabel 可选属性：
- 从工作台打开时传入"产品 / 项目 / 版本"路径
- 显示在 Drawer 顶部灰色背景条中
- 从版本详情打开时不传，不显示（无需冗余）
- 统一样式：px-5 py-2 bg-[var(--bg-subtle)] text-[11px]

涉及组件：
- PlanDetailDrawer
- DevTaskDetailDrawer
- TestCaseDetailDrawer
- BugDetailDrawer

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

apps/web/components/version/PlanDetailDrawer.tsx

@@ -11,13 +11,14 @@ import type { PlanTask, VersionPlan } from '@/lib/version-plan';
 interface Props {
   planId: string;
   onClose: () => void;
+  contextLabel?: string;
 }
 
 const STATUS_STYLE: Record<string, string> = { pending: 'bg-zinc-100 text-zinc-600', in_progress: 'bg-blue-50 text-blue-600', completed: 'bg-emerald-50 text-emerald-600' };
 const STATUS_LABEL: Record<string, string> = { pending: '未开始', in_progress: '进行中', completed: '已完成' };
 const TYPE_LABEL: Record<string, string> = { research: '调研', product: '产品方案', ui: 'UI设计' };
 
-export function PlanDetailDrawer({ planId, onClose }: Props) {
+export function PlanDetailDrawer({ planId, onClose, contextLabel }: Props) {
   const { plans, updatePlan, completePlan } = useVersionPlanStore();
   const { requirements } = useRequirementStore();
   const { members } = useMemberStore();
@@ -77,6 +78,12 @@ export function PlanDetailDrawer({ planId, onClose }: Props) {
   return (
     <div className="fixed inset-0 z-50 flex justify-end" onClick={onClose}>
       <div className="w-full max-w-md h-full bg-[var(--bg)] border-l border-[var(--line)] shadow-2xl flex flex-col overflow-hidden" onClick={(e) => e.stopPropagation()}>
+        {/* Context */}
+        {contextLabel && (
+          <div className="px-5 py-2 border-b border-[var(--line)] bg-[var(--bg-subtle)] shrink-0">
+            <span className="text-[11px] text-[var(--ink-muted)]">{contextLabel}</span>
+          </div>
+        )}
         {/* Header */}
         <div className="flex items-center justify-between px-5 py-4 border-b border-[var(--line)] shrink-0">
           <div className="flex items-center gap-2">