feat: shop customer accounts (register/login + order history)

Schema:
- shop_customers (company_id, name, phone unique-per-tenant, email, password,
  client_id auto-linked, last_login_at)
- online_orders.shop_customer_id nullable FK

Auth:
- New 'shop' guard (session driver, shop_customers provider) in config/auth.php
- ShopCustomer Authenticatable with hashed password cast and BelongsToTenant
  global scope — login attempts naturally scoped to current tenant subdomain

Flow:
- ShopAuthController: register / login / logout / account
- Register auto-links to existing Client by phone match
- /shop/account: order history (only the logged customer's orders) + profile
- Checkout prefills name/phone/email from logged customer + sets
  shop_customer_id (and client_id from auto-link) on the placed order
- Layout nav switches between Login/Register and "👤 Name + Ieșire"

Tests (8 new):
- register creates customer + auto-login
- register auto-links existing Client by phone
- duplicate phone rejected
- login validates credentials
- /account requires auth (redirects to /shop/login)
- /account lists only the logged customer's orders
- checkout attaches shop_customer_id
- customers tenant-isolated

Full suite: 117 passed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

database/migrations/2026_06_02_120000_create_shop_customers.php

@@ -0,0 +1,43 @@
+<?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('shop_customers', function (Blueprint $t) {
+            $t->id();
+            $t->foreignId('company_id')->constrained()->cascadeOnDelete();
+            $t->foreignId('client_id')->nullable()->constrained()->nullOnDelete();
+            $t->string('name', 160);
+            $t->string('phone', 40);
+            $t->string('email', 160)->nullable();
+            $t->string('password');
+            $t->dateTime('last_login_at')->nullable();
+            $t->rememberToken();
+            $t->timestamps();
+            $t->softDeletes();
+
+            $t->unique(['company_id', 'phone'], 'shop_customers_company_phone_unique');
+            $t->index(['company_id', 'email']);
+        });
+
+        Schema::table('online_orders', function (Blueprint $t) {
+            $t->foreignId('shop_customer_id')->nullable()->after('client_id')
+                ->constrained()->nullOnDelete();
+            $t->index(['company_id', 'shop_customer_id']);
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('online_orders', function (Blueprint $t) {
+            $t->dropForeign(['shop_customer_id']);
+            $t->dropColumn('shop_customer_id');
+        });
+        Schema::dropIfExists('shop_customers');
+    }
+};