feat(04-01): install new deps + scaffold API test harness with Wave-0 RED stubs

- Add react-router@7, @dnd-kit/core, @dnd-kit/sortable, fractional-indexing to PWA
- Add fractional-indexing to API (rank generation server-side)
- ioredis NOT added (in-memory EventEmitter per RESEARCH Plan 02 justification)
- Create apps/api/test/setup.ts with afterEach DB cleanup for list tables
- Wire test.setupFiles in apps/api/vitest.config.ts
- Add 4 Wave-0 RED stub test files (LIST-01/02/03/04, D-04, D-11, D-07)
- All stubs run as todo, not import-error

apps/pwa/package.json

@@ -11,6 +11,8 @@
     "test": "vitest run"
   },
   "dependencies": {
+    "@dnd-kit/core": "^6.3.1",
+    "@dnd-kit/sortable": "^10.0.0",
     "@schedule-x/calendar": "4.6.0",
     "@schedule-x/calendar-controls": "4.6.0",
     "@schedule-x/event-modal": "4.6.0",
@@ -18,10 +20,12 @@
     "@schedule-x/react": "4.1.0",
     "@schedule-x/theme-default": "4.6.0",
     "@tanstack/react-query": "5.101.0",
+    "fractional-indexing": "^3.2.0",
     "ical.js": "2.2.1",
     "lucide-react": "1.17.0",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
+    "react-router": "^7.17.0",
     "temporal-polyfill": "0.3.2",
     "vite-plugin-pwa": "^1.3.0",
     "zustand": "5.0.14"