Issue with keys containing "-" due to schema changes in PR #82 affecting ACF and WP Post properties merging

[Zmetser]

Description

Before the changes introduced in PR #82, properties from ACF and WP Post properties that shared keys with "-" in their names were merged under the same key in the generated schema.

After the changes in this PR, instead of merging under the same key, a new separate key is added specifically for the WP Post properties.

Example for before

{
  "components": {
    "schemas": {
      "foo-bar": {
        "title": "Foo Bar",
        "type": "object",
        "properties": {
          // WP Core
          "slug": {
            "description": "An alphanumeric identifier for the post unique to its type.",
            "type": "string"
          },
          "title": { ... },
          ...
          // ACF
          "topper": { ...},
          "credits": { ... }
        }
    }
  }
}

Example for after

Observe how what was unified under foo-bar before, now separated under two keys foo-bar and foo_bar

{
  "components": {
    "schemas": {
      // WP Core
      "foo_bar": {
        "title": "Foo Bar",
        "type": "object",
        "properties": {
          "slug": {
            "description": "An alphanumeric identifier for the post unique to its type.",
            "type": "string"
          },
          "title": { ... },
      },
      // ACF
      "foo-bar": {
        "topper": { ... },
        "credits": { ... }
      }
    }
  }
}

Expected Behavior

Previously, both ACF and WP Post properties with matching keys (including those containing "-") were included together under a single schema key (e.g., "foo-bar"). This merging made it possible to interact with all related fields in one place.

Actual Behavior

After PR #82, these properties are now split into separate schema entries, such as "foo-bar" for ACF and "foo_bar" for WP Core, resulting in fragmentation and possible breaking changes for users expecting the unified schema.