feat: PIN gate on Λειτουργίες settings tab (code: 4034)

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

manager_dashboard/src/pages/Settings/tabs/Phase2FeaturesTab.jsx

@@ -1,5 +1,54 @@
+import { useState } from 'react'
 import { PHASE2_FEATURE_DEFS, isFeatureEnabled, setFeatureEnabled, usePhase2Features } from '../../../hooks/usePhase2Features'
 
+const SECRET = '4034'
+
+function PinGate({ onUnlock }) {
+  const [pin, setPin] = useState('')
+  const [error, setError] = useState(false)
+
+  function submit() {
+    if (pin === SECRET) {
+      onUnlock()
+    } else {
+      setError(true)
+      setPin('')
+      setTimeout(() => setError(false), 1500)
+    }
+  }
+
+  return (
+    <div className="flex flex-col items-center justify-center gap-5 py-16 max-w-xs mx-auto">
+      <div className="flex h-12 w-12 items-center justify-center rounded-xl bg-slate-100 text-2xl">🔒</div>
+      <div className="text-center">
+        <p className="font-semibold text-slate-800">Περιορισμένη πρόσβαση</p>
+        <p className="text-sm text-slate-400 mt-1">Εισάγετε τον κωδικό για να συνεχίσετε</p>
+      </div>
+      <div className="flex flex-col items-center gap-3 w-full">
+        <input
+          type="password"
+          value={pin}
+          onChange={e => setPin(e.target.value)}
+          onKeyDown={e => e.key === 'Enter' && submit()}
+          autoFocus
+          maxLength={8}
+          placeholder="••••"
+          className={`w-full text-center text-xl tracking-[0.4em] border rounded-xl px-4 py-3 outline-none transition-colors ${
+            error ? 'border-red-400 bg-red-50 text-red-600' : 'border-slate-200 focus:border-sky-400'
+          }`}
+        />
+        {error && <p className="text-xs text-red-500 font-medium">Λάθος κωδικός</p>}
+        <button
+          onClick={submit}
+          className="w-full rounded-xl bg-slate-900 text-white font-semibold py-2.5 text-sm hover:bg-slate-700 transition-colors"
+        >
+          Είσοδος
+        </button>
+      </div>
+    </div>
+  )
+}
+
 function Toggle({ checked, onChange }) {
   return (
     <button
@@ -22,8 +71,11 @@ function Toggle({ checked, onChange }) {
 }
 
 export default function Phase2FeaturesTab() {
+  const [unlocked, setUnlocked] = useState(false)
   const features = usePhase2Features()
 
+  if (!unlocked) return <PinGate onUnlock={() => setUnlocked(true)} />
+
   const allOn  = features.every(f => f.enabled)
   const allOff = features.every(f => !f.enabled)