feat(FN-3208): restore mobile nodes nav and improve planning mode

This merge delivers significant testing infrastructure refactoring alongside focused UI, planning, and plugin features. The largest change splits the 20K-line `routes.test.ts` monolith into 15 granular route test files (agents, auth, automation, git, github, planning, settings, system, tasks, tasks-

Fusion-Task-Id: FN-3208

packages/dashboard/app/App.tsx

@@ -1046,6 +1046,7 @@ function AppInner() {
         onOpenActivityLog={modalManager.openActivityLog}
         onOpenSystemStats={modalManager.openSystemStats}
         onOpenMailbox={() => handleTaskViewChange("mailbox")}
+        onOpenNodes={handleOpenNodes}
         mailboxUnreadCount={mailboxUnreadCount}
         onOpenGitManager={modalManager.openGitManager}
         onOpenWorkflowSteps={modalManager.openWorkflowSteps}
@@ -1072,6 +1073,7 @@ function AppInner() {
           devServerView: devServerEnabled,
           todoView: todosEnabled,
           researchView: researchEnabled,
+          nodesView: nodesEnabled,
         }}
         pluginDashboardViews={pluginDashboardViews}
       />