Initial commit: SuiviCPT personal finance tracker

Laravel 11 + Livewire 3/Volt + Alpine.js + Tailwind app for household
budget planning, transaction tracking, and financial dashboards.

- Multi-tenant households with member invites
- Plan: monthly/yearly budget per category with overrides
- Suivi: transaction log with running balance (desktop + mobile quick-entry)
- Dashboard: budget vs tracked breakdown + Chart.js donuts
- Flux: Sankey diagram of income allocation
- WCAG 2.1 AA color tokens, dark mode, accessible tables/forms
- 50 Pest tests

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

app/Models/BudgetLine.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+class BudgetLine extends Model
+{
+    protected $fillable = ['household_id', 'category_id', 'year', 'month', 'amount'];
+
+    protected function casts(): array
+    {
+        return [
+            'amount' => 'decimal:2',
+        ];
+    }
+
+    public function household(): BelongsTo
+    {
+        return $this->belongsTo(Household::class);
+    }
+
+    public function category(): BelongsTo
+    {
+        return $this->belongsTo(Category::class);
+    }
+
+    public function scopeForYear(Builder $query, int $year): Builder
+    {
+        return $query->where('year', $year);
+    }
+
+    public function scopeDefaultLine(Builder $query): Builder
+    {
+        return $query->whereNull('month');
+    }
+
+    public function scopeForMonth(Builder $query, int $month): Builder
+    {
+        return $query->where('month', $month);
+    }
+}