reset to setup module state

Remove Task Manager implementation to match `# Setup module` in module.md.
Backend src/ reduced to Kernel.php + empty Entity/, all migrations deleted,
database dropped and recreated. Frontend components/views/services/stores
removed, App.vue/router/style.css reduced to skeletons. CLAUDE.md shortened
to Setup-stand. Old backend/plan.md, plan2.md removed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/src/Enum/TaskSchemaStatus.php

@@ -1,9 +0,0 @@
-<?php
-
-namespace App\Enum;
-
-enum TaskSchemaStatus: string
-{
-    case Active = 'active';
-    case Disabled = 'disabled';
-}

backend/src/Enum/TaskSchemaType.php

@@ -1,10 +0,0 @@
-<?php
-
-namespace App\Enum;
-
-enum TaskSchemaType: string
-{
-    case Single = 'single';
-    case Daily = 'daily';
-    case Custom = 'custom';
-}

backend/src/Enum/TaskStatus.php

@@ -1,9 +0,0 @@
-<?php
-
-namespace App\Enum;
-
-enum TaskStatus: string
-{
-    case Active = 'active';
-    case Done = 'done';
-}