feat: auto-convert URL to QR code in PDF export and preview

app/routes/plans.py

@@ -832,6 +832,29 @@ def preview_report(plan_id):
     # Markdown 转 HTML
     html_content = markdown.markdown(rendered, extensions=['tables', 'fenced_code'])
 
+    # URL 转二维码图片（预览用）
+    import re
+    import qrcode
+    import base64
+    from io import BytesIO
+
+    def make_qr_base64(url):
+        qr = qrcode.make(url, box_size=5)
+        buf = BytesIO()
+        qr.save(buf, format='PNG')
+        return base64.b64encode(buf.getvalue()).decode()
+
+    def replace_url_with_qr(match):
+        url = match.group(0)
+        try:
+            qr_b64 = make_qr_base64(url)
+            return f'<br><img src="data:image/png;base64,{qr_b64}" alt="QR" style="width:80px;display:block;margin:8px auto;">'
+        except:
+            return url
+
+    url_pattern = re.compile(r'https?://[^\s<>"{}|\\^`\[\]]+')
+    html_content = url_pattern.sub(replace_url_with_qr, html_content)
+
     # 支持 ReportLab <para alignment="center"> 语法，转为 HTML
     import re
     html_content = re.sub(