fix(notifications): implement toWebhook() for always-send notifications

WebhookChannel::send() calls toWebhook() unconditionally, but the five
notifications reachable through alwaysSendEvents did not implement it, so
enabling the webhook channel turned those events into fatal queued jobs.

app/Notifications/ApiTokenExpiringNotification.php

@@ -100,4 +100,16 @@ class ApiTokenExpiringNotification extends CustomEmailNotification
             color: SlackMessage::warningColor(),
         );
     }
+
+    public function toWebhook(): array
+    {
+        return [
+            'success' => false,
+            'message' => "API token '{$this->tokenName}' expires on {$this->expiresAt}. Rotate this token before it expires to avoid API outages.",
+            'event' => 'api_token_expiring',
+            'token_name' => $this->tokenName,
+            'expires_at' => $this->expiresAt,
+            'url' => $this->manageUrl,
+        ];
+    }
 }

app/Notifications/Internal/GeneralNotification.php

@@ -58,4 +58,14 @@ class GeneralNotification extends Notification implements ShouldQueue
             color: SlackMessage::infoColor(),
         );
     }
+
+    public function toWebhook(): array
+    {
+        return [
+            'success' => true,
+            'message' => $this->message,
+            'event' => 'general',
+            'url' => base_url(),
+        ];
+    }
 }

app/Notifications/Server/ForceDisabled.php

@@ -74,4 +74,16 @@ class ForceDisabled extends CustomEmailNotification
             color: SlackMessage::errorColor()
         );
     }
+
+    public function toWebhook(): array
+    {
+        return [
+            'success' => false,
+            'message' => "Server ({$this->server->name}) disabled because it is not paid! All automations and integrations are stopped.",
+            'event' => 'server_force_disabled',
+            'server_name' => $this->server->name,
+            'server_uuid' => $this->server->uuid,
+            'url' => base_url().'/server/'.$this->server->uuid,
+        ];
+    }
 }

app/Notifications/Server/ForceEnabled.php

@@ -65,4 +65,16 @@ class ForceEnabled extends CustomEmailNotification
             color: SlackMessage::successColor()
         );
     }
+
+    public function toWebhook(): array
+    {
+        return [
+            'success' => true,
+            'message' => "Server ({$this->server->name}) enabled again!",
+            'event' => 'server_force_enabled',
+            'server_name' => $this->server->name,
+            'server_uuid' => $this->server->uuid,
+            'url' => base_url().'/server/'.$this->server->uuid,
+        ];
+    }
 }

app/Notifications/SslExpirationNotification.php

@@ -148,4 +148,18 @@ class SslExpirationNotification extends CustomEmailNotification
             color: SlackMessage::warningColor()
         );
     }
+
+    public function toWebhook(): array
+    {
+        $resourceNames = $this->resources->pluck('name');
+
+        return [
+            'success' => false,
+            'message' => "SSL certificates have been renewed for: {$resourceNames->join(', ')}. These resources need to be redeployed manually for the new SSL certificates to take effect.",
+            'event' => 'ssl_certificate_renewal',
+            'resources' => $resourceNames->values()->all(),
+            'urls' => $this->urls,
+            'url' => base_url(),
+        ];
+    }
 }