add email signup flow

backend/database/migrations/0001_01_01_000000_create_users_table.php

@@ -11,7 +11,7 @@ return new class extends Migration
         Schema::create('users', function (Blueprint $table): void {
             $table->id();
             $table->string('email')->unique();
-            $table->string('passwordHash');
+            $table->string('passwordHash')->nullable();
         });
     }
 

backend/database/migrations/2026_08_03_000000_create_email_confirmation_tokens_table.php

@@ -0,0 +1,29 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::create(
+            'email_confirmation_tokens',
+            function (Blueprint $table): void {
+                $table->id();
+                $table->foreignId('user_id')
+                    ->unique()
+                    ->constrained('users')
+                    ->cascadeOnDelete();
+                $table->string('token', 64)->unique();
+                $table->timestamp('available_to');
+            },
+        );
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('email_confirmation_tokens');
+    }
+};