fix(audit): stop duplicate and empty audit rows

- Set env var version and compose parsing version while creating, so a create writes one row
- Record no rows for the auto-created preview copy of an env var
- Record env and application API updates only with the fields that really changed
- Store no change data for new env vars, and null for empty change data
- Store metadata team_id as an integer
- Drop the unused level and resource indexes of audit_events

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Models/Service.php

@@ -100,10 +100,7 @@ class Service extends BaseModel
             if (blank($service->name)) {
                 $service->name = 'service-'.new_public_id();
             }
-        });
-        static::created(function ($service) {
             $service->compose_parsing_version = self::$parserVersion;
-            $service->save();
         });
         static::saving(function ($service) {
             if ($service->isDirty('docker_compose_raw')) {