fix: AI 摘要复制失败 — HTTP 环境 Clipboard API 不可用

navigator.clipboard 需要安全上下文(HTTPS/localhost),
内网 HTTP 部署时自动降级为 textarea + execCommand('copy')

frontend/src/views/desktop/WeeklyReport.vue

@@ -120,10 +120,21 @@ async function generateAISummary() {
 
 async function copySummary() {
   if (!aiSummary.value) return
+  const plain = aiSummary.value.replace(/^#{1,4}\s+/gm, '').replace(/\*\*/g, '').replace(/\*/g, '')
   try {
-    // Strip markdown markers for plain text
-    const plain = aiSummary.value.replace(/^#{1,4}\s+/gm, '').replace(/\*\*/g, '').replace(/\*/g, '')
-    await navigator.clipboard.writeText(plain)
+    // Prefer Clipboard API (requires HTTPS or localhost)
+    if (navigator.clipboard && window.isSecureContext) {
+      await navigator.clipboard.writeText(plain)
+    } else {
+      // Fallback for HTTP environments
+      const ta = document.createElement('textarea')
+      ta.value = plain
+      ta.style.position = 'fixed'; ta.style.left = '-9999px'; ta.style.top = '-9999px'
+      document.body.appendChild(ta)
+      ta.focus(); ta.select()
+      document.execCommand('copy')
+      document.body.removeChild(ta)
+    }
     ElMessage.success('摘要已复制到剪贴板')
   } catch {
     ElMessage.error('复制失败')