feat(web): initialize Next.js project with Tailwind CSS and TypeScript setup

pkg/engine/types.go

@@ -0,0 +1,15 @@
+package engine
+
+import (
+	"context"
+
+	"github.com/lyzrai/flow/pkg/models"
+)
+
+// NodeExecutorFunc is the signature for executing a single node.
+// Each registered node type provides one of these.
+type NodeExecutorFunc func(ctx context.Context, node models.NodeDef, inputs [][]models.Item, execCtx *ExecutionContext) (map[int][]models.Item, error)
+
+// ExecutorLookup resolves a node type string to a node executor function.
+// The runner uses this to dispatch each node to its registered handler.
+type ExecutorLookup func(nodeType string) (NodeExecutorFunc, error)