feat(embeddings): add embedding model support and related changes

* Introduced EmbeddingModel method in Client and Provider interfaces
* Updated InsertThought and SearchThoughts methods to handle embedding models
* Created embeddings table and updated match_thoughts function for model filtering
* Removed embedding column from thoughts table
* Adjusted permissions for new embeddings table

internal/app/app.go

@@ -40,7 +40,7 @@ func Run(ctx context.Context, configPath string) error {
 	}
 	defer db.Close()
 
-	if err := db.VerifyRequirements(ctx, cfg.AI.Embeddings.Dimensions); err != nil {
+	if err := db.VerifyRequirements(ctx); err != nil {
 		return err
 	}