Require auth for the web UI, keep the JSON API open

Sites/Social Accounts/Posts pages now require login; add a Login
Livewire component, guest layout, and logout action. routes/api.php
is untouched, per AI_API.md's documented no-auth-by-design contract.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

resources/views/livewire/auth/login.blade.php

@@ -0,0 +1,26 @@
+<div class="bg-white p-8 rounded-lg shadow border border-gray-200">
+    <h1 class="text-xl font-semibold mb-6">Muninn</h1>
+
+    <form wire:submit="login" class="space-y-4">
+        <div>
+            <label class="block text-sm font-medium mb-1" for="email">Email</label>
+            <input type="email" id="email" wire:model="email" class="w-full rounded border-gray-300" autofocus>
+            @error('email') <p class="text-sm text-red-600 mt-1">{{ $message }}</p> @enderror
+        </div>
+
+        <div>
+            <label class="block text-sm font-medium mb-1" for="password">Password</label>
+            <input type="password" id="password" wire:model="password" class="w-full rounded border-gray-300">
+            @error('password') <p class="text-sm text-red-600 mt-1">{{ $message }}</p> @enderror
+        </div>
+
+        <label class="flex items-center gap-2 text-sm">
+            <input type="checkbox" wire:model="remember">
+            Remember me
+        </label>
+
+        <button type="submit" class="w-full bg-blue-600 text-white rounded py-2 font-medium hover:bg-blue-700">
+            Log in
+        </button>
+    </form>
+</div>