feat(backend): make repository_url optional when launching agents

- Remove validation requiring repository_url in lifecycleAdapter.LaunchAgent
- Skip workspace mounts in lifecycle manager when no workspace path is provided
- Agents can now run without a pre-existing workspace directory

apps/backend/cmd/kandev/main.go

@@ -519,17 +519,12 @@ func newLifecycleAdapter(mgr *lifecycle.Manager, reg *registry.Registry, log *lo
 
 // LaunchAgent starts a new agent container for a task
 func (a *lifecycleAdapter) LaunchAgent(ctx context.Context, req *executor.LaunchAgentRequest) (*executor.LaunchAgentResponse, error) {
-	// The RepositoryURL field should contain a local filesystem path for the workspace
-	// If it's empty, we cannot mount the workspace into the container
-	workspacePath := req.RepositoryURL
-	if workspacePath == "" {
-		return nil, fmt.Errorf("task has no repository_url configured - please set a local repository path on the task")
-	}
-
+	// The RepositoryURL field contains a local filesystem path for the workspace
+	// If empty, the agent will run without a mounted workspace
 	launchReq := &lifecycle.LaunchRequest{
 		TaskID:          req.TaskID,
 		AgentType:       req.AgentType,
-		WorkspacePath:   workspacePath,
+		WorkspacePath:   req.RepositoryURL, // May be empty - lifecycle manager handles this
 		TaskDescription: req.TaskDescription,
 		Metadata:        req.Metadata,
 	}

apps/backend/internal/agent/lifecycle/manager.go

@@ -789,6 +789,12 @@ func (m *Manager) buildContainerConfig(instanceID string, req *LaunchRequest, ag
 	// Expand mount templates
 	mounts := make([]docker.MountConfig, 0, len(agentConfig.Mounts))
 	for _, mt := range agentConfig.Mounts {
+		// Skip workspace mounts if no workspace path is provided
+		if strings.Contains(mt.Source, "{workspace}") && req.WorkspacePath == "" {
+			m.logger.Debug("skipping workspace mount - no workspace path provided",
+				zap.String("target", mt.Target))
+			continue
+		}
 		source := m.expandMountTemplate(mt.Source, req.WorkspacePath, req.TaskID)
 		mounts = append(mounts, docker.MountConfig{
 			Source:   source,