feat: módulo embedding — encode, model CRUD, stores sqlvec y usearch

Funciones Python para embeddings: carga/guardado de modelos, encoding de
texto, y almacenamiento/búsqueda vectorial con sqlite-vec y usearch.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

python/functions/embedding/__init__.py

@@ -0,0 +1,5 @@
+"""Embedding functions — model management, encoding, and vector storage/retrieval."""
+
+from embedding.model import embedding_save_model, embedding_load_model, embedding_encode
+from embedding.sqlvec import embedding_store_sqlvec, embedding_search_sqlvec
+from embedding.usearch_store import embedding_store_usearch, embedding_search_usearch