‼️ Part of critical path ‼️
Needed for: #180141 and #180128

Summary

This PR replaces the incorrect Zod schema for the ruleSource rule param.

Previously, the rule source field schema was implemented using a Zod transformation that automatically converted the snake-cased is_customized attribute to its camel-cased version isCustomized.

const RuleSourceCamelCased = RuleSource.transform(convertObjectKeysToCamelCase);

const RuleSource = z.object({
  type: z.literal('external'),
  is_customized: IsExternalRuleCustomized,
});

However, this meant that the expected input type for the schema was snake-cased, as the transformation happened only after validation.

Valid payload before:

{
  "ruleSource": {
    "type": "external",
    "is_customized": false // <- it should be camel cased
  }
}

To overcome this issue, the rule source schema was implemented without using the transformation (revert #180121).

Valid payload after:

{
  "ruleSource": {
    "type": "external",
    "isCustomized": false
  }
}

Important Note

This rule param schema change is considered safe because we do not currently use this field in the code. All values of this field are currently undefined. However, to ensure a Serverless release rollout without breaking changes, we need to release this schema change before we start writing any actual data.