Add recurring transactions with monthly confirmation flow

New "Récurrences" section lets users define recurring depense/epargne
models (name, category, default amount, day of month). Nothing is
created automatically: from the day a recurrence is due, it appears
as a pending proposal in Suivi (desktop + mobile) with an editable
amount, so variable bills (electricity, etc.) can be adjusted before
confirming. Dismissing a proposal skips it for the current month
without creating a transaction, and it reappears the following month.

- recurring_transactions table (household/category scoped, active flag,
  last_generated_year/month to prevent duplicate generation)
- transactions.recurring_transaction_id nullable FK to trace origin
- RecurringTransactionPolicy mirrors CategoryPolicy tenant scoping
- 10 new Pest tests covering CRUD, tenant isolation, and the
  pending/confirm/dismiss lifecycle across month boundaries (travelTo)

58/58 tests pass, Pint clean, verified end-to-end against production
data (test recurrence created and cleaned up).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/Models/Household.php

@@ -44,4 +44,9 @@ class Household extends Model
     {
         return $this->hasMany(HouseholdInvite::class);
     }
+
+    public function recurringTransactions(): HasMany
+    {
+        return $this->hasMany(RecurringTransaction::class);
+    }
 }

app/Models/RecurringTransaction.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+class RecurringTransaction extends Model
+{
+    protected $fillable = [
+        'household_id', 'category_id', 'name', 'amount', 'day_of_month',
+        'active', 'last_generated_year', 'last_generated_month',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'amount' => 'decimal:2',
+            'active' => 'boolean',
+        ];
+    }
+
+    public function household(): BelongsTo
+    {
+        return $this->belongsTo(Household::class);
+    }
+
+    public function category(): BelongsTo
+    {
+        return $this->belongsTo(Category::class);
+    }
+
+    public function transactions(): HasMany
+    {
+        return $this->hasMany(Transaction::class);
+    }
+
+    public function wasGeneratedFor(int $year, int $month): bool
+    {
+        return $this->last_generated_year === $year && $this->last_generated_month === $month;
+    }
+}

app/Models/Transaction.php

@@ -9,7 +9,7 @@ use Illuminate\Database\Eloquent\Relations\BelongsTo;
 
 class Transaction extends Model
 {
-    protected $fillable = ['household_id', 'category_id', 'user_id', 'date', 'date_effective', 'amount', 'details'];
+    protected $fillable = ['household_id', 'category_id', 'recurring_transaction_id', 'user_id', 'date', 'date_effective', 'amount', 'details'];
 
     protected function casts(): array
     {