feat(121+122): smsplanet conversation, notifications, default footer

Phase 121 — SMSPLANET Conversation + Notifications:
- migration 20260512_000110 adds smsplanet conversation + notifications tables
- src/Modules/Sms (SmsConversationService, SmsMessageRepository, SmsplanetWebhookController)
- src/Modules/Notifications (Repository, Controller, ApiController)
- order SMS tab, notification center, sender mode, inbound webhook
- public notifications.js + layouts/app.php integration

Phase 122 — SMSPLANET Default SMS Footer:
- migration 20260512_000111 adds smsplanet_integration_settings.default_footer
- footer appended to test SMS and order SMS, validated against 918 char limit
- settings textarea + compact order SMS note when footer configured

Bundled (could not split per-phase without hunk staging):
- routes/web.php (also carries Phase 118 fakturownia redirects)
- DOCS/{ARCHITECTURE,DB_SCHEMA,TECH_CHANGELOG}.md (118 + 121 + 122 entries)
- .paul/codebase/{architecture,db_schema,tech_changelog}.md (118 + 121 + 122)
- .paul/STATE.md, ROADMAP.md, changelog/2026-05-12.md (UNIFY closure)

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

resources/views/layouts/app.php

@@ -177,6 +177,13 @@
         <div>
           <strong><?= $e((string) (($user['name'] ?? '') !== '' ? $user['name'] : ($user['email'] ?? ''))) ?></strong>
         </div>
+        <a class="topbar-notifications" href="/notifications" id="js-notification-button" title="<?= $e($t('notifications.title')) ?>" aria-label="<?= $e($t('notifications.title')) ?>">
+          <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.9" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
+            <path d="M18 8a6 6 0 10-12 0c0 7-3 7-3 9h18c0-2-3-2-3-9"/>
+            <path d="M13.73 21a2 2 0 01-3.46 0"/>
+          </svg>
+          <span class="topbar-notifications__badge" id="js-notification-badge" hidden>0</span>
+        </a>
         <form action="/logout" method="post">
           <input type="hidden" name="_token" value="<?= $e($csrfToken ?? '') ?>">
           <button type="submit" class="btn btn--secondary"><?= $e($t('actions.logout')) ?></button>
@@ -206,6 +213,7 @@
   <script src="/assets/js/modules/invoice-requested-toggle.js?ver=<?= filemtime(dirname(__DIR__, 3) . '/public/assets/js/modules/invoice-requested-toggle.js') ?: 0 ?>"></script>
   <script src="/assets/js/modules/confirm-delete.js?ver=<?= filemtime(dirname(__DIR__, 3) . '/public/assets/js/modules/confirm-delete.js') ?: 0 ?>"></script>
   <script src="/assets/js/modules/alert-dismiss.js?ver=<?= filemtime(dirname(__DIR__, 3) . '/public/assets/js/modules/alert-dismiss.js') ?: 0 ?>"></script>
+  <script src="/assets/js/modules/notifications.js?ver=<?= filemtime(dirname(__DIR__, 3) . '/public/assets/js/modules/notifications.js') ?: 0 ?>"></script>
   <script src="https://cdn.jsdelivr.net/npm/chart.js@4.4.8/dist/chart.umd.min.js"></script>
   <script src="/assets/js/modules/statistics-summary-charts.js?ver=<?= filemtime(dirname(__DIR__, 3) . '/public/assets/js/modules/statistics-summary-charts.js') ?: 0 ?>"></script>
   <script>