Implement automation in debug engine out of the box

**Is your feature request related to a problem? Please describe (REQUIRED):**
It's important for development process with agents to be frictionless. Point an agent to a defold project, and it should be able to figure out how to work with it, including launching editor, game, sending input, taking screenshots, etc.

**Describe the solution you'd like (REQUIRED):**
Automation should be available out of the box in debug builds, discoverable using openapi (#12335).

**Describe alternatives you've considered (REQUIRED):**
Keep it as extension and recommend users to install it.

Start by reviewing the existing automation extension and the OpenAPI discovery work in issue #12335, then determine how debug builds expose editor, game, input, and screenshot automation. Done means those capabilities are available out of the box in debug builds and are discoverable through OpenAPI without installing an extension.

Written by the indexing model from the issue text.