feat: add notification infrastructure with database channel, enum, and notification classes (Story 3.1)

Set up Laravel notification system with NotificationType enum (5 types),
NudgeNotification, DocumentUploadedNotification, and DeclarationOverdueNotification
classes with database + mail channels. Add email templates, infrastructure tests,
and fix existing NotificationController tests for workspace compatibility.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/Enums/NotificationType.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Enums;
+
+use BenSampo\Enum\Enum;
+
+final class NotificationType extends Enum
+{
+    const Nudge = 'nudge';
+
+    const DeclarationOverdue = 'declaration_overdue';
+
+    const DocumentUploaded = 'document_uploaded';
+
+    const BulkNotification = 'bulk_notification';
+
+    const StatusChanged = 'status_changed';
+
+    /**
+     * Get French display labels for each notification type.
+     *
+     * @return array<string, string>
+     */
+    public static function labels(): array
+    {
+        return [
+            self::Nudge => 'Relance',
+            self::DeclarationOverdue => 'Déclaration en retard',
+            self::DocumentUploaded => 'Document téléversé',
+            self::BulkNotification => 'Notification groupée',
+            self::StatusChanged => 'Statut modifié',
+        ];
+    }
+}

app/Mail/NudgeNotificationMail.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Mail;
+
+use App\Models\Declaration;
+use App\Models\User;
+use Illuminate\Bus\Queueable;
+use Illuminate\Mail\Mailable;
+use Illuminate\Mail\Mailables\Content;
+use Illuminate\Mail\Mailables\Envelope;
+use Illuminate\Queue\SerializesModels;
+
+class NudgeNotificationMail extends Mailable
+{
+    use Queueable, SerializesModels;
+
+    public function __construct(
+        public Declaration $declaration,
+        public User $sender,
+    ) {}
+
+    public function envelope(): Envelope
+    {
+        return new Envelope(
+            subject: 'Relance - '.($this->declaration->title ?? 'Sans titre'),
+        );
+    }
+
+    public function content(): Content
+    {
+        return new Content(
+            markdown: 'emails.nudge-notification',
+            with: [
+                'senderName' => $this->sender->name,
+                'clientName' => $this->declaration->client?->name,
+                'declarationType' => $this->declaration->type?->value,
+                'dueDate' => $this->declaration->due_date?->format('d/m/Y'),
+                'url' => route('declarations.show', $this->declaration),
+                'firmName' => $this->declaration->workspace?->name,
+            ]
+        );
+    }
+}

app/Notifications/DeclarationOverdueNotification.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Notifications;
+
+use App\Enums\NotificationType;
+use App\Models\Declaration;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Notifications\Messages\MailMessage;
+use Illuminate\Notifications\Notification;
+
+class DeclarationOverdueNotification extends Notification implements ShouldQueue
+{
+    use Queueable;
+
+    public int $tries = 3;
+
+    public int $backoff = 60;
+
+    public bool $deleteWhenMissingModels = true;
+
+    public function __construct(
+        public Declaration $declaration,
+    ) {}
+
+    /**
+     * @return array<string>
+     */
+    public function via(object $notifiable): array
+    {
+        return ['database', 'mail'];
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function toDatabase(object $notifiable): array
+    {
+        return [
+            'workspace_id' => $this->declaration->workspace_id,
+            'declaration_id' => $this->declaration->id,
+            'notification_type' => NotificationType::DeclarationOverdue,
+        ];
+    }
+
+    public function toMail(object $notifiable): MailMessage
+    {
+        return (new MailMessage)
+            ->subject('Déclaration en retard - '.($this->declaration->title ?? 'Sans titre'))
+            ->markdown('emails.declaration-overdue', [
+                'declarationTitle' => $this->declaration->title ?? 'Sans titre',
+                'dueDate' => $this->declaration->due_date?->format('d/m/Y'),
+                'url' => route('declarations.show', $this->declaration),
+            ]);
+    }
+}

app/Notifications/DocumentUploadedNotification.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace App\Notifications;
+
+use App\Enums\NotificationType;
+use App\Models\Declaration;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Notifications\Notification;
+
+class DocumentUploadedNotification extends Notification implements ShouldQueue
+{
+    use Queueable;
+
+    public bool $deleteWhenMissingModels = true;
+
+    public function __construct(
+        public Declaration $declaration,
+        public int $clientId,
+    ) {}
+
+    /**
+     * @return array<string>
+     */
+    public function via(object $notifiable): array
+    {
+        return ['database'];
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function toDatabase(object $notifiable): array
+    {
+        return [
+            'workspace_id' => $this->declaration->workspace_id,
+            'declaration_id' => $this->declaration->id,
+            'client_id' => $this->clientId,
+            'notification_type' => NotificationType::DocumentUploaded,
+        ];
+    }
+}

app/Notifications/NudgeNotification.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace App\Notifications;
+
+use App\Enums\NotificationType;
+use App\Mail\NudgeNotificationMail;
+use App\Models\Declaration;
+use App\Models\User;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Notifications\Notification;
+
+class NudgeNotification extends Notification implements ShouldQueue
+{
+    use Queueable;
+
+    public int $tries = 3;
+
+    public int $backoff = 60;
+
+    public bool $deleteWhenMissingModels = true;
+
+    public function __construct(
+        public Declaration $declaration,
+        public User $sender,
+    ) {}
+
+    /**
+     * @return array<string>
+     */
+    public function via(object $notifiable): array
+    {
+        return ['database', 'mail'];
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function toDatabase(object $notifiable): array
+    {
+        return [
+            'workspace_id' => $this->declaration->workspace_id,
+            'declaration_id' => $this->declaration->id,
+            'sender_id' => $this->sender->id,
+            'notification_type' => NotificationType::Nudge,
+        ];
+    }
+
+    public function toMail(object $notifiable): NudgeNotificationMail
+    {
+        return new NudgeNotificationMail($this->declaration, $this->sender);
+    }
+}