feat: add apm.yml for platform-mode configuration and dependencies

[danielmeppiel]

This pull request introduces a new apm.yml file to the project.

It allows platform-mode to become an APM module that others can install by adding it to their APM dependencies file:

name: my-project
version: 1.0.0
description: This project uses Platform-mode
author: danielmeppiel

dependencies:
  apm:
    - DevExpGbb/platform-mode

scripts:
  discovery-codex: "RUST_LOG=debug codex --skip-git-repo-check discovery.prompt.md"
  # Continue exposing any scripts from the package

And then, once spec-kit PR is merged

specify apm install
specify apm run discovery-codex

[raykao]

Looks straight forward and good to me 😄
thanks @danielmeppiel