feat: login page, session management, auth API routes en proxy guard

- lib/session.ts: token generatie, SHA-256 hashing, createSession/getCurrentUser/invalidateSession
- app/api/auth/login: bcrypt verificatie, session aanmaken, ops_session cookie (httpOnly, sameSite=strict, 24h TTL), rate-limit 5/min per IP
- app/api/auth/logout: session invalideren en cookie verwijderen
- app/login/page.tsx: login form (client component)
- proxy.ts: route-protectie – redirect naar /login zonder sessie (middleware.ts is deprecated in Next.js 16)

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

app/login/page.tsx

@@ -0,0 +1,97 @@
+'use client'
+
+import { useState } from 'react'
+import { useRouter } from 'next/navigation'
+import { Button } from '@/components/ui/button'
+
+export default function LoginPage() {
+  const router = useRouter()
+  const [email, setEmail] = useState('')
+  const [password, setPassword] = useState('')
+  const [error, setError] = useState('')
+  const [loading, setLoading] = useState(false)
+
+  async function handleSubmit(e: React.FormEvent) {
+    e.preventDefault()
+    setError('')
+    setLoading(true)
+
+    try {
+      const res = await fetch('/api/auth/login', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ email, password }),
+      })
+
+      if (res.ok) {
+        router.push('/')
+        router.refresh()
+      } else {
+        const data = await res.json()
+        setError(data.error ?? 'Login failed')
+      }
+    } catch {
+      setError('Network error, please try again')
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  return (
+    <div className="flex min-h-full items-center justify-center bg-zinc-50 dark:bg-zinc-950">
+      <div className="w-full max-w-sm rounded-xl border border-zinc-200 bg-white p-8 shadow-sm dark:border-zinc-800 dark:bg-zinc-900">
+        <h1 className="mb-6 text-xl font-semibold text-zinc-900 dark:text-zinc-50">
+          Ops Dashboard
+        </h1>
+
+        <form onSubmit={handleSubmit} className="flex flex-col gap-4">
+          <div className="flex flex-col gap-1.5">
+            <label
+              htmlFor="email"
+              className="text-sm font-medium text-zinc-700 dark:text-zinc-300"
+            >
+              Email
+            </label>
+            <input
+              id="email"
+              type="email"
+              autoComplete="email"
+              required
+              value={email}
+              onChange={(e) => setEmail(e.target.value)}
+              className="rounded-lg border border-zinc-300 bg-white px-3 py-2 text-sm text-zinc-900 outline-none placeholder:text-zinc-400 focus:border-zinc-500 focus:ring-2 focus:ring-zinc-500/20 dark:border-zinc-700 dark:bg-zinc-800 dark:text-zinc-50 dark:placeholder:text-zinc-500 dark:focus:border-zinc-400"
+              placeholder="admin@example.com"
+            />
+          </div>
+
+          <div className="flex flex-col gap-1.5">
+            <label
+              htmlFor="password"
+              className="text-sm font-medium text-zinc-700 dark:text-zinc-300"
+            >
+              Password
+            </label>
+            <input
+              id="password"
+              type="password"
+              autoComplete="current-password"
+              required
+              value={password}
+              onChange={(e) => setPassword(e.target.value)}
+              className="rounded-lg border border-zinc-300 bg-white px-3 py-2 text-sm text-zinc-900 outline-none placeholder:text-zinc-400 focus:border-zinc-500 focus:ring-2 focus:ring-zinc-500/20 dark:border-zinc-700 dark:bg-zinc-800 dark:text-zinc-50 dark:placeholder:text-zinc-500 dark:focus:border-zinc-400"
+              placeholder="••••••••"
+            />
+          </div>
+
+          {error && (
+            <p className="text-sm text-red-600 dark:text-red-400">{error}</p>
+          )}
+
+          <Button type="submit" disabled={loading} className="mt-2 w-full">
+            {loading ? 'Signing in…' : 'Sign in'}
+          </Button>
+        </form>
+      </div>
+    </div>
+  )
+}