refactor(phase7): Initialize JobRunner in factory.go

- Create jobRunner using NewJobRunner with local and container executors
- Assign jobRunner to Worker.runner field
- JobRunner available for future task execution orchestration

Build status: Compiles successfully

internal/worker/factory.go

@@ -126,6 +126,14 @@ func NewWorker(cfg *Config, _ string) (*Worker, error) {
 		cfg.LocalMode,
 	)
 
+	// Create job runner
+	jobRunner := executor.NewJobRunner(
+		localExecutor,
+		containerExecutor,
+		nil, // ManifestWriter - can be added later if needed
+		logger,
+	)
+
 	runLoop := lifecycle.NewRunLoop(
 		runLoopConfig,
 		queueClient,
@@ -150,6 +158,7 @@ func NewWorker(cfg *Config, _ string) (*Worker, error) {
 		config:    cfg,
 		logger:    logger,
 		runLoop:   runLoop,
+		runner:    jobRunner,
 		metrics:   metricsObj,
 		health:    lifecycle.NewHealthMonitor(),
 		resources: rm,