refactor: sjednoceni zdroje casu na MySQL NOW() + audit log cleanup a UI

- attendance handlery pouzivaji getDbNow() misto PHP date()
- nova helper funkce getDbNow() v AttendanceHelpers.php
- audit log: cleanup endpoint (POST) s volbou stari zaznamu
- audit log: filtry na jednom radku
- dashboard: aktivita prejmenovana na Audit log s odkazem

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

src/admin/components/dashboard/DashActivityFeed.jsx

@@ -1,3 +1,4 @@
+import { Link } from 'react-router-dom'
 import { ENTITY_TYPE_LABELS, getActivityIconClass, formatActivityTime } from '../../utils/dashboardHelpers'
 
 function getActivityIcon(action) {
@@ -43,8 +44,9 @@ export default function DashActivityFeed({ activities }) {
 
   return (
     <div className="admin-card dash-activity-card">
-      <div className="admin-card-header">
-        <h2 className="admin-card-title">Poslední aktivita</h2>
+      <div className="admin-card-header" style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
+        <h2 className="admin-card-title">Audit log</h2>
+        <Link to="/audit-log" className="admin-btn admin-btn-primary admin-btn-sm">Detail &rarr;</Link>
       </div>
       <div className="admin-card-body" style={{ padding: 0 }}>
         {activities.map((act) => (

src/admin/pages/AuditLog.jsx

@@ -76,6 +76,9 @@ export default function AuditLog() {
     date_from: '',
     date_to: '',
   })
+  const [showCleanup, setShowCleanup] = useState(false)
+  const [cleanupDays, setCleanupDays] = useState(90)
+  const [cleaning, setCleaning] = useState(false)
 
   const fetchLogs = useCallback(async (page = 1, perPage = 50) => {
     setLoading(true)
@@ -139,6 +142,29 @@ export default function AuditLog() {
     fetchLogs(1, newPerPage)
   }
 
+  const handleCleanup = async () => {
+    setCleaning(true)
+    try {
+      const response = await apiFetch(`${API_BASE}/audit-log.php`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ action: 'cleanup', days: cleanupDays }),
+      })
+      const data = await response.json()
+      if (data.success) {
+        alert.success(data.message)
+        setShowCleanup(false)
+        fetchLogs()
+      } else {
+        alert.error(data.error)
+      }
+    } catch {
+      alert.error('Chyba připojení')
+    } finally {
+      setCleaning(false)
+    }
+  }
+
   const formatDatetime = (dateString) => {
     if (!dateString) {
       return '-'
@@ -195,8 +221,74 @@ export default function AuditLog() {
             </p>
           )}
         </div>
+        <button
+          className="admin-btn admin-btn-secondary admin-btn-sm"
+          onClick={() => setShowCleanup(true)}
+        >
+          <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
+            <polyline points="3 6 5 6 21 6" />
+            <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
+          </svg>
+          Vyčistit
+        </button>
       </motion.div>
 
+      {showCleanup && (
+        <div className="admin-modal-overlay" style={{ opacity: 1 }}>
+          <div className="admin-modal-backdrop" onClick={() => !cleaning && setShowCleanup(false)} />
+          <motion.div
+            className="admin-modal admin-confirm-modal"
+            initial={{ opacity: 0, scale: 0.95, y: 20 }}
+            animate={{ opacity: 1, scale: 1, y: 0 }}
+            transition={{ duration: 0.2 }}
+          >
+            <div className="admin-modal-body admin-confirm-content">
+              <div className="admin-confirm-icon admin-confirm-icon-danger">
+                <svg width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
+                  <polyline points="3 6 5 6 21 6" />
+                  <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
+                </svg>
+              </div>
+              <h2 className="admin-confirm-title">Vyčistit audit log</h2>
+              <p className="admin-confirm-message">Smazat záznamy starší než:</p>
+              <div style={{ margin: '0.75rem auto', maxWidth: '200px' }}>
+                <select
+                  className="admin-form-select"
+                  value={cleanupDays}
+                  onChange={(e) => setCleanupDays(parseInt(e.target.value))}
+                >
+                  <option value={30}>30 dní</option>
+                  <option value={60}>60 dní</option>
+                  <option value={90}>90 dní</option>
+                  <option value={180}>180 dní</option>
+                  <option value={365}>1 rok</option>
+                  <option value={0}>Vše</option>
+                </select>
+              </div>
+              <p className="admin-confirm-message" style={{ fontSize: '12px', opacity: 0.6 }}>Tato akce je nevratná.</p>
+            </div>
+            <div className="admin-modal-footer">
+              <button
+                type="button"
+                onClick={() => setShowCleanup(false)}
+                className="admin-btn admin-btn-secondary"
+                disabled={cleaning}
+              >
+                Zrušit
+              </button>
+              <button
+                type="button"
+                onClick={handleCleanup}
+                className="admin-btn admin-btn-primary"
+                disabled={cleaning}
+              >
+                {cleaning ? 'Mažu...' : 'Smazat'}
+              </button>
+            </div>
+          </motion.div>
+        </div>
+      )}
+
       <motion.div
         className="admin-card"
         initial={{ opacity: 0, y: 20 }}
@@ -205,7 +297,7 @@ export default function AuditLog() {
         style={{ marginBottom: '1rem' }}
       >
         <div className="admin-card-body">
-          <div className="admin-form-row" style={{ gridTemplateColumns: '2fr 1fr 1fr' }}>
+          <div className="admin-form-row" style={{ gridTemplateColumns: '1.2fr 1fr 1fr 1fr 1fr' }}>
             <FormField label="Hledat">
               <input
                 type="text"
@@ -239,8 +331,6 @@ export default function AuditLog() {
                 ))}
               </select>
             </FormField>
-          </div>
-          <div className="admin-form-row" style={{ gridTemplateColumns: '1fr 1fr', maxWidth: '400px', marginTop: '0.75rem' }}>
             <FormField label="Od">
               <AdminDatePicker
                 mode="date"