feat: Add Google Cloud Storage CDN for models.soulcraft.com

- Primary source: models.soulcraft.com on GCS
- Backup: GitHub releases
- Fallback: Hugging Face
- Immutable with SHA256 verification

dist/utils/embedding.js

@@ -3,6 +3,7 @@
  * Complete rewrite to eliminate TensorFlow.js and use ONNX-based models
  */
 import { isBrowser } from './environment.js';
+import { ModelManager } from '../embeddings/model-manager.js';
 // @ts-ignore - Transformers.js is now the primary embedding library
 import { pipeline, env } from '@huggingface/transformers';
 /**
@@ -192,6 +193,9 @@ export class TransformerEmbedding {
         }
         // Always use real implementation - no mocking
         try {
+            // Ensure models are available (downloads if needed)
+            const modelManager = ModelManager.getInstance();
+            await modelManager.ensureModels(this.options.model);
             // Resolve device configuration and cache directory
             const device = await resolveDevice(this.options.device);
             const cacheDir = this.options.cacheDir === './models'