perf(ui): виртуализация реестра задач и чата (@tanstack/react-virtual)

Шаг 1.3 плана production-готовности:
- TaskRegistry: виртуальные строки с динамической высотой, порог 30
- TaskChat: виртуальные сообщения, порог 100, автоскролл/scrollToMessage
- выделение/сортировка/поиск/inline-редакторы работают по полному массиву
- check/build чисто, vitest 96/96

package-lock.json

@@ -54,6 +54,7 @@
         "@radix-ui/react-tooltip": "^1.2.0",
         "@sendgrid/mail": "^8.1.5",
         "@tanstack/react-query": "^5.60.5",
+        "@tanstack/react-virtual": "^3.14.11",
         "@tiptap/extension-color": "^3.27.0",
         "@tiptap/extension-highlight": "^3.27.0",
         "@tiptap/extension-image": "^3.27.0",
@@ -5693,6 +5694,33 @@
         "react": "^18 || ^19"
       }
     },
+    "node_modules/@tanstack/react-virtual": {
+      "version": "3.14.11",
+      "resolved": "https://registry.npmjs.org/@tanstack/react-virtual/-/react-virtual-3.14.11.tgz",
+      "integrity": "sha512-SStWf8bYdTgAquYqG4Pi2+d1XimQKoCIJ94H3jsm0D6UA0yqffvWuvUzrrQ4idewFWq8BSPpahnmLVosJIAs6g==",
+      "license": "MIT",
+      "dependencies": {
+        "@tanstack/virtual-core": "3.17.9"
+      },
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/tannerlinsley"
+      },
+      "peerDependencies": {
+        "react": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0",
+        "react-dom": "^16.8.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
+      }
+    },
+    "node_modules/@tanstack/virtual-core": {
+      "version": "3.17.9",
+      "resolved": "https://registry.npmjs.org/@tanstack/virtual-core/-/virtual-core-3.17.9.tgz",
+      "integrity": "sha512-M8Bzy7CCMvUjRiuoHVH9mRjyUVczRs8v8RcUEphLFGc445ZP4KQ15Y1sLqhQqJi/HgGJrxfCHnEnIX0x9mVrBg==",
+      "license": "MIT",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/tannerlinsley"
+      }
+    },
     "node_modules/@tiptap/core": {
       "version": "3.27.1",
       "resolved": "https://registry.npmjs.org/@tiptap/core/-/core-3.27.1.tgz",