Implement ID-based routing and folder auto-generation from titles

Major features:
- Switch from slug-based to ID-based routing (/documents/123)
- Enable title editing with automatic slug/path regeneration
- Auto-generate folder structure from title slashes (e.g., Laravel/Livewire/Components)
- Persist sidebar folder open/close state using localStorage
- Remove slug unique constraint (ID routing makes it unnecessary)
- Implement recursive tree view with multi-level folder support

Architecture changes:
- DocumentService: Add generatePathAndSlug() for title-based path generation
- Routes: Change from {document:slug} to {document} for ID binding
- SidebarTree: Extract recursive rendering to partials/tree-item.blade.php
- Database: Remove unique constraint from documents.slug column

UI improvements:
- Display only last path component in sidebar (Components vs Laravel/Livewire/Components)
- Folder state persists across page navigation via localStorage
- Title field accepts slashes for folder organization

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/tests/Feature/Auth/PasswordConfirmationTest.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace Tests\Feature\Auth;
+
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class PasswordConfirmationTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_confirm_password_screen_can_be_rendered(): void
+    {
+        $user = User::factory()->create();
+
+        $response = $this->actingAs($user)->get('/confirm-password');
+
+        $response->assertStatus(200);
+    }
+
+    public function test_password_can_be_confirmed(): void
+    {
+        $user = User::factory()->create();
+
+        $response = $this->actingAs($user)->post('/confirm-password', [
+            'password' => 'password',
+        ]);
+
+        $response->assertRedirect();
+        $response->assertSessionHasNoErrors();
+    }
+
+    public function test_password_is_not_confirmed_with_invalid_password(): void
+    {
+        $user = User::factory()->create();
+
+        $response = $this->actingAs($user)->post('/confirm-password', [
+            'password' => 'wrong-password',
+        ]);
+
+        $response->assertSessionHasErrors();
+    }
+}