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/tools/update.go

@@ -48,7 +48,7 @@ func (t *UpdateTool) Handle(ctx context.Context, _ *mcp.CallToolRequest, in Upda
 	}
 
 	content := current.Content
-	embedding := current.Embedding
+	var embedding []float32
 	mergedMetadata := current.Metadata
 	projectID := current.ProjectID
 
@@ -79,7 +79,7 @@ func (t *UpdateTool) Handle(ctx context.Context, _ *mcp.CallToolRequest, in Upda
 		projectID = &project.ID
 	}
 
-	updated, err := t.store.UpdateThought(ctx, id, content, embedding, mergedMetadata, projectID)
+	updated, err := t.store.UpdateThought(ctx, id, content, embedding, t.provider.EmbeddingModel(), mergedMetadata, projectID)
 	if err != nil {
 		return nil, UpdateOutput{}, err
 	}