feat: E.164 phone validation and storage with libphonenumber

- Add giggsey/libphonenumber-for-php, PhoneNumberNormalizer, ValidPhoneNumber rule

- Store subscribers as E.164; mutator normalizes on save; optional phone required from form block

- Migration to normalize legacy subscriber phones; Mailwizz/search/UI/tests updated

- Add run-deploy-from-local.sh and PREREGISTER_DEFAULT_PHONE_REGION in .env.example

Made-with: Cursor

database/migrations/2026_04_04_220000_normalize_existing_subscriber_phones_to_e164.php

@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\Subscriber;
+use App\Services\PhoneNumberNormalizer;
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        if (! Schema::hasTable('subscribers')) {
+            return;
+        }
+
+        /** @var PhoneNumberNormalizer $normalizer */
+        $normalizer = app(PhoneNumberNormalizer::class);
+
+        Subscriber::query()
+            ->whereNotNull('phone')
+            ->where('phone', '!=', '')
+            ->orderBy('id')
+            ->chunkById(100, function ($subscribers) use ($normalizer): void {
+                foreach ($subscribers as $subscriber) {
+                    $p = $subscriber->phone;
+                    if (! is_string($p) || $p === '') {
+                        continue;
+                    }
+
+                    if (str_starts_with($p, '+')) {
+                        $normalized = $normalizer->normalizeToE164($p);
+                        if ($normalized !== null && $normalized !== $p) {
+                            $subscriber->update(['phone' => $normalized]);
+                        }
+
+                        continue;
+                    }
+
+                    if (preg_match('/^\d{8,15}$/', $p) !== 1) {
+                        continue;
+                    }
+
+                    $normalized = $normalizer->normalizeToE164('+'.$p);
+                    if ($normalized !== null) {
+                        $subscriber->update(['phone' => $normalized]);
+                    }
+                }
+            });
+    }
+
+    public function down(): void
+    {
+        // Irreversible: we cannot recover original user input formatting.
+    }
+};