Function resolveDotenvWithConfigLoader

Resolve dotenv values using the config-loader/overlay path (always-on in host/generator flows; no-op when no config files are present).

Order:

1. Compute base from files only (exclude dynamic; ignore programmatic vars).
2. Discover packaged + project config sources and overlay onto base.
3. Apply dynamics in order: programmatic dynamic > config dynamic (packaged → project public → project local) > file dynamicPath.
4. Phase C interpolation of remaining string options (e.g., outputPath).
5. Optionally write outputPath, log, and merge into process.env.