Extract prompt sources and rendering internals

internal/prompt/renderer.go

@@ -0,0 +1,11 @@
+package prompt
+
+import (
+	"context"
+	"gitea.maximumdirect.net/eric/promptkit/internal/domain"
+)
+
+// Renderer renders prompt templates using named artifacts and variables.
+type Renderer interface {
+	Render(ctx context.Context, definition *domain.PromptDefinition, inputs map[string]*domain.Artifact, vars map[string]string) (*domain.RenderedPrompt, error)
+}