feat: add mobile-responsive layout and card views across all pages

- New useIsMobile hook and MobileCardList component
- AppLayout: hamburger menu + Drawer navigation on mobile
- All list pages (Inbox, Posteingang, Manuell, Mail, Freigabe, Zahlung, TaskLog)
  show card layout on mobile instead of tables
- CSS: responsive modal height, horizontal table scroll, text-size-adjust
- Backend: Agrarmonitor polling fixes, Zahlung service improvements,
  IMAP folder service extended, misc controller fixes

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

paperless-frontend/src/components/DocumentEditModal.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useState, useCallback } from 'react';
 import { Modal, Form, Select, DatePicker, Input, Spin, message, Row, Col, Button, Space, Divider, Tag } from 'antd';
-import { PlusOutlined, EyeOutlined, SearchOutlined } from '@ant-design/icons';
+import { PlusOutlined, EyeOutlined, SearchOutlined, ExportOutlined } from '@ant-design/icons';
 import dayjs from 'dayjs';
 import { posteingangApi } from '../api/posteingang';
 import type { DocumentRequirement, PosteingangDocument, Kontonummer } from '../api/posteingang';
@@ -11,6 +11,7 @@ import type { PaperlessDocType, PaperlessCorrespondent, PaperlessTag } from '../
 import { getEnv } from '../utils/env';
 import { AuthIframe, openAuthUrl } from '../utils/auth-resource';
 import DocumentSearchModal from './DocumentSearchModal';
+import { useIsMobile } from '../hooks/useIsMobile';
 
 const { Option } = Select;
 
@@ -26,6 +27,7 @@ interface Props {
 
 export default function DocumentEditModal({ documentId, document, open, onClose, onSave, isPosteingang = true, hasNextDocument = true }: Props) {
   const [form] = Form.useForm();
+  const isMobile = useIsMobile();
   
   const [loading, setLoading] = useState(false);
   const [saving, setSaving] = useState(false);
@@ -349,8 +351,8 @@ export default function DocumentEditModal({ documentId, document, open, onClose,
         title={`Dokument bearbeiten (${document?.title || ''})`}
         open={open && !kontonummerMissing}
         onCancel={() => onClose(false)}
-        width={1400}
-        style={{ top: 20 }}
+        width={{ xs: '100vw', md: 900, xl: 1400 }}
+        style={isMobile ? {} : { top: 20 }}
         footer={
            hasNextDocument ? [
                <Button key="cancel" onClick={() => onClose(false)}>Abbrechen</Button>,
@@ -363,8 +365,12 @@ export default function DocumentEditModal({ documentId, document, open, onClose,
         }
       >
         <Spin spinning={loading}>
-            <Row gutter={16} style={{ height: '75vh', overflow: 'hidden' }}>
-                <Col span={10} style={{ overflowY: 'auto', paddingRight: '1rem', borderRight: '1px solid #f0f0f0' }}>
+            <Row gutter={[16, 16]} style={isMobile ? {} : { height: '75vh', overflow: 'hidden' }}>
+                <Col
+                    xs={24}
+                    lg={10}
+                    style={isMobile ? {} : { overflowY: 'auto', paddingRight: '1rem', borderRight: '1px solid #f0f0f0' }}
+                >
                     <Form form={form} layout="vertical" disabled={saving}>
                         
                         <Form.Item name="mandant" label="Mandant" rules={[{ required: true, message: 'Wähle einen Mandanten' }]}>
@@ -556,10 +562,20 @@ export default function DocumentEditModal({ documentId, document, open, onClose,
                         })}
                     </Form>
                 </Col>
-                <Col span={14} style={{ height: '100%' }}>
+                <Col xs={24} lg={14} style={isMobile ? {} : { height: '100%' }}>
+                    {isMobile && (
+                        <Button
+                            icon={<ExportOutlined />}
+                            block
+                            style={{ marginBottom: 8 }}
+                            onClick={() => openAuthUrl(`${getEnv('VITE_API_URL')}/api/paperless/inbox/pdf/${documentId}`)}
+                        >
+                            PDF in neuem Tab öffnen
+                        </Button>
+                    )}
                     <AuthIframe
                       src={`${getEnv('VITE_API_URL')}/api/paperless/inbox/pdf/${documentId}#toolbar=0`}
-                      style={{ width: '100%', height: '100%' }}
+                      style={{ width: '100%', height: isMobile ? '50vh' : '100%' }}
                       title="PDF Preview"
                     />
                 </Col>