fix(web): 伴飞分段条响应式不溢出 + 深度过程步骤箭头更友好

- 伴飞(copilot)分段进度条:按钮加 min-w-0(flex 子项默认 min-width:auto 不收缩 → truncate 失效 →
  6步时溢出截断),序号圈加 flex-none。现在多段自适应收缩 + 省略,不再被右侧切掉。
- 深度过程面板:展开标识改成'右指箭头→展开旋90°朝下'的经典 disclosure(更清晰友好)+ 整行 hover 高亮 +
  aria-expanded;detail 缩进对齐按钮 padding。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/pac-web/src/components/plan-detail/script-deep-process.tsx

@@ -44,25 +44,29 @@ export function ScriptDeepProcess({ steps }: { steps: DeepStep[] }) {
               <button
                 type="button"
                 onClick={hasDetail ? toggle : undefined}
-                className={`flex w-full items-center gap-2 text-left ${hasDetail ? 'cursor-pointer' : 'cursor-default'}`}
+                aria-expanded={hasDetail ? open : undefined}
+                className={`flex w-full items-center gap-2 rounded px-1.5 py-1 text-left transition-colors ${
+                  hasDetail ? 'cursor-pointer hover:bg-slate-100' : 'cursor-default'
+                }`}
               >
                 <StepIcon status={s.status} />
                 <span className="font-medium text-slate-700">{STEP_LABEL[s.step]}</span>
                 {s.status === 'running' && <span className="shimmer-text text-slate-400">…</span>}
                 {hasDetail && (
+                  // 右指箭头(收起)→ 旋转 90° 朝下(展开):清晰的可展开标识
                   <svg
                     viewBox="0 0 24 24"
                     fill="none"
                     stroke="currentColor"
-                    strokeWidth="2"
-                    className={`ml-auto h-3 w-3 flex-none text-slate-400 transition-transform ${open ? 'rotate-180' : ''}`}
+                    strokeWidth="2.5"
+                    className={`ml-auto h-3.5 w-3.5 flex-none text-slate-400 transition-transform ${open ? 'rotate-90' : ''}`}
                   >
-                    <path d="M6 9l6 6 6-6" strokeLinecap="round" strokeLinejoin="round" />
+                    <path d="M9 6l6 6-6 6" strokeLinecap="round" strokeLinejoin="round" />
                   </svg>
                 )}
               </button>
               {hasDetail && open && (
-                <div className="mt-1 pl-[22px]">
+                <div className="mt-1 pl-7">
                   <StepDetail step={s} />
                 </div>
               )}

apps/pac-web/src/components/plan-detail/script-viewer.tsx

@@ -99,7 +99,7 @@ export function ScriptCopilot({ sections, streaming = false }: { sections: Scrip
             key={s.id}
             onClick={() => setActive(i)}
             className={cn(
-              'flex-1 text-[11px] font-medium px-2 py-1.5 rounded transition-colors flex items-center justify-center gap-1.5',
+              'flex-1 min-w-0 text-[11px] font-medium px-2 py-1.5 rounded transition-colors flex items-center justify-center gap-1.5',
               i === active
                 ? 'bg-teal-600 text-white shadow-sm'
                 : i < active
@@ -109,7 +109,7 @@ export function ScriptCopilot({ sections, streaming = false }: { sections: Scrip
           >
             <span
               className={cn(
-                'w-4 h-4 rounded-full flex items-center justify-center text-[9.5px]',
+                'w-4 h-4 flex-none rounded-full flex items-center justify-center text-[9.5px]',
                 i === active
                   ? 'bg-white/20 text-white'
                   : i < active