E2E CI pipeline mit ephemerer Infrastruktur

- drone.yml: deploy_latest Pipeline mit k3s test-backend, OpenTofu
  E2E-VMs, E2E-Test-Ausführung, Email-Notification und Cleanup
- Alte tag/promote Pipelines auskommentiert
- APK build/upload vorerst auskommentiert
- E2E test runner script (scripts/e2e-test.sh)
- tsconfig: expo/tsconfig.base Extension
- CLAUDE.md an neue CI/CD-Struktur angepasst

tsconfig.json

@@ -3,8 +3,15 @@
     "strict": true
   },
   "references": [
-    { "path": "packages/shared" },
-    { "path": "apps/client" },
-    { "path": "apps/server" }
-  ]
+    {
+      "path": "packages/shared"
+    },
+    {
+      "path": "apps/client"
+    },
+    {
+      "path": "apps/server"
+    }
+  ],
+  "extends": "expo/tsconfig.base"
 }