feat: add uploader.generate to generate and upload AI images

[mckomo-cl]

Brief Summary of Changes

Adds a new cloudinary.v2.uploader.generate() method that generates an image from a text prompt using Cloudinary's image generation API and uploads the generated image to your product environment — in a single call.

• New method uploader.generate(generateParams, options, callback) — the same envelope as uploader.upload, but the first argument carries the generation parameters (prompt is required; model_family, quality_tier, model_id, width, height, seed are optional).
• Internally it calls the image generation API and then uploads the resulting image (via the secure_url returned by the generation API) by delegating to uploader.upload. The resolved value / callback result is therefore the upload response, so all standard upload options (folder, tags, context, metadata, …) are honored.
• On a generation failure the error is propagated using the standard SDK error handling (rejected promise + error callback); the upload step is not attempted.
• New internal API client call_generate_api (JSON body + Basic Auth / OAuth) mirroring call_analysis_api, plus a base_processing_api_url helper for the v2 processing endpoint.
• TypeScript types added (GenerateImageOptions interface and generate overloads).

Usage

const cloudinary = require('cloudinary').v2;

cloudinary.config({
  cloud_name: 'my_cloud',
  api_key: '************',
  api_secret: '************',
});

// Generate an image from a prompt and upload it with advanced upload options.
const result = await cloudinary.uploader.generate(
  {
    prompt: 'A photorealistic sunset over a mountain lake, 8K detail',
    model_family: 'flux',
    quality_tier: 'premium',
    width: 1024,
    height: 768,
  },
  {
    folder: 'ai/landscapes',
    tags: ['ai-generated', 'sunset'],
    context: { alt: 'AI generated sunset', caption: 'Mountain lake at dusk' },
  },
);

console.log(result);
// The resolved value is the *upload* response of the generated image, e.g.:
// {
//   asset_id: 'a1b2c3d4e5f60718293a4b5c6d7e8f90',
//   public_id: 'ai/landscapes/xyz789',
//   version: 1718600000,
//   signature: 'abcdef1234567890abcdef1234567890abcdef12',
//   width: 1024,
//   height: 768,
//   format: 'png',
//   resource_type: 'image',
//   created_at: '2026-06-17T10:30:00Z',
//   tags: ['ai-generated', 'sunset'],
//   bytes: 2048576,
//   type: 'upload',
//   etag: '7f1e2d3c4b5a69788',
//   url: 'http://res.cloudinary.com/my_cloud/image/upload/v1718600000/ai/landscapes/xyz789.png',
//   secure_url: 'https://res.cloudinary.com/my_cloud/image/upload/v1718600000/ai/landscapes/xyz789.png',
//   folder: 'ai/landscapes',
//   context: { custom: { alt: 'AI generated sunset', caption: 'Mountain lake at dusk' } },
//   original_filename: 'xyz789',
// }

Callback style is also supported, identical to upload:

cloudinary.uploader.generate(
  { prompt: 'A man with a hat' },
  { folder: 'ai/portraits', tags: ['ai-generated'] },
  (error, result) => {
    console.log(result, error);
  },
);

What Does This PR Address?

• GitHub issue (Add reference - #XX)
• Refactoring
• New feature
• Bug fix
• Adds more tests

Are Tests Included?

• Yes
• No

Reviewer, Please Note:

• The generation endpoint uses JSON + Basic Auth (like the Admin / Analysis APIs), not the multipart/signed transport used by upload. The new call_generate_api client handles this and reuses the existing API key/secret (or OAuth) configuration — no extra auth setup is required.
• generate returns the upload result (not the generation response) by design, so it behaves as a drop-in for upload with a prompt instead of a file path.
• Tests follow the existing conventions (sinon stub of https.request, assertions mirroring analyze_spec/debug_mode_spec); no new test utilities were added.