i18n vocabulaire exos (fr/pt-BR) + Web Push rappels de série

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

functional/streaks/database/migrations/2026_07_19_013000_add_last_reminded_on_to_streaks.php

@@ -0,0 +1,23 @@
+<?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::table('streaks', function (Blueprint $table) {
+            // Date du dernier rappel push envoyé (anti-doublon : 1 rappel/jour max).
+            $table->date('last_reminded_on')->nullable()->after('freeze_last_granted_on');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('streaks', function (Blueprint $table) {
+            $table->dropColumn('last_reminded_on');
+        });
+    }
+};