fix(api): hide sensitive fields by default, expose via makeVisible for privileged tokens

Models now declare $hidden for passwords, tokens, db URLs, and compose
fields. API controllers flip from makeHidden-on-deny to makeVisible-on-
allow (can_read_sensitive=true), fixing fields that were never hidden.
Also adds missing fields (mysql/mariadb passwords, logdrain keys, etc.)
to privileged disclosure lists.

Tests added: Feature/Security/ApiSensitiveFieldsTest and
Unit/Models/SensitiveFieldsHiddenTest cover all affected models and
controllers.

app/Http/Controllers/Api/ServicesController.php

@@ -30,8 +30,8 @@ class ServicesController extends Controller
             'resourceable_id',
             'resourceable_type',
         ]);
-        if (request()->attributes->get('can_read_sensitive', false) === false) {
-            $service->makeHidden([
+        if (request()->attributes->get('can_read_sensitive', false) === true) {
+            $service->makeVisible([
                 'docker_compose_raw',
                 'docker_compose',
                 'value',