feat: typed options object for the Node.js API

[robertsLando]

The current public API (lib/index.ts) accepts a raw string[] mimicking CLI argv:

export async function exec(argv: string[])

This forces programmatic consumers to construct CLI-style argument arrays, which is error-prone, untyped, and undiscoverable:

// Current — no type safety, easy to get wrong
await exec(['project/', '--targets', 'node22-linux-x64', '--sea', '-C', 'Brotli']);

Proposal

Introduce a typed options interface and an overload or new entry point:

interface PkgOptions {
  input: string;
  targets?: string[];
  output?: string;
  outputPath?: string;
  compress?: 'None' | 'Brotli' | 'GZip';
  sea?: boolean;
  debug?: boolean;
  bytecode?: boolean;
  // ...
}

export async function exec(options: PkgOptions): Promise<void>;
// Keep backward compat:
export async function exec(argv: string[]): Promise<void>;

Scope

• Define PkgOptions interface (reuse/extend existing internal types from lib/types.ts)
• Support both string[] (backward compat) and PkgOptions overloads
• Export the types from the package entry point
• Document the new API in the docs site

Part of #235