feat: L'Ami Fiduciaire V1.0.0 — full codebase with Story 0.1 complete

Initial commit of the L'Ami Fiduciaire SaaS platform built on Laravel 12,
Vue 3, Inertia.js 2, and Tailwind CSS 4.

Story 0.1 (rename folders to declarations in database) is implemented and
code-reviewed: migration, rollback, and 6 Pest tests all passing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Mail/FolderFileRequestMail.php

@@ -0,0 +1,51 @@
+<?php
+
+namespace App\Mail;
+
+use App\Models\Folder;
+use App\Models\FolderInvitation;
+use Illuminate\Bus\Queueable;
+use Illuminate\Mail\Mailable;
+use Illuminate\Mail\Mailables\Content;
+use Illuminate\Mail\Mailables\Envelope;
+use Illuminate\Queue\SerializesModels;
+
+class FolderFileRequestMail extends Mailable
+{
+    use Queueable, SerializesModels;
+
+    /**
+     * Create a new message instance.
+     */
+    public function __construct(
+        public Folder $folder,
+        public FolderInvitation $invitation,
+        public string $body
+    ) {}
+
+    /**
+     * Get the message envelope.
+     */
+    public function envelope(): Envelope
+    {
+        return new Envelope(
+            subject: 'Documents complémentaires demandés - '.$this->folder->title,
+        );
+    }
+
+    /**
+     * Get the message content definition.
+     */
+    public function content(): Content
+    {
+        return new Content(
+            markdown: 'emails.folder-file-request',
+            with: [
+                'folderTitle' => $this->folder->title,
+                'body' => $this->body,
+                'uploadUrl' => route('client.upload', ['token' => $this->invitation->token]),
+                'expiresAt' => $this->invitation->expires_at->format('d/m/Y à H:i'),
+            ]
+        );
+    }
+}