execute: add WithToolRegistry/WithSkillsRegistry Options

Ensures every Server created by the dispatcher factory has registries
wired at construction time, fixing intermittent 'no session registry'
errors from tool_load/skill_load.

pkg/tools/execute/server.go

@@ -122,6 +122,20 @@ func (e *Server) AllowTools() []string {
 	return out
 }
 
+
+// WithToolRegistry attaches a tool registry and session ID to the Server.
+func WithToolRegistry(r *Registry, sessionID string) Option {
+	return func(s *Server) {
+		s.toolRegistry = r
+		s.sessionID = sessionID
+	}
+}
+
+// WithSkillsRegistry attaches a skills registry to the Server.
+func WithSkillsRegistry(r *skills.Registry) Option {
+	return func(s *Server) { s.skillsRegistry = r }
+}
+
 // Decl returns a factory for an execute Server with the given working directory.
 func Decl(cwd string, opts ...Option) func() tools.Server {
 	return func() tools.Server {