test+ci: 51 frontend unit-тестов (Vitest) + CI rollback на single resolve-tag

Tests (Vitest):
- src/lib/dates.ts (вынесено из SchemaDrivenForm + dictionaries.$name): parseFormDate,
  formatIsoDate, formatIsoDateTime, extractTime, combineDateTime, localTzOffset, nowIsoLocal
- src/lib/dates.test.ts (20 tests): TZ-safety, pure-date local midnight, far-future filter,
  round-trip parse/format, time extraction в local TZ, clear-button (null Date → '')
- src/components/schema/types.test.ts (31 tests): buildSchemaJson всех 9 kinds + x-unique +
  x-id-source, parseSchemaJson roundtrip, diffSchemas (8 breaking detection cases),
  suggestVersionBump (major/minor/patch + breaking-wins-mix)

CI:
- Откатил dual resolve-tag (BACKEND/FRONTEND) на single resolve-tag.
  GitLab variable interpolation в trigger jobs не подхватывает dotenv от needs-job
  → admin-ui-only push не доезжал до infra. Now backwards compat path работает
  как раньше с UPSTREAM_IMAGE_TAG.
- Backend docker jobs (maven-package + 4 docker-*) теперь без rules:changes —
  catch ImagePullBackOff если frontend push шёл без backend rebuild. BuildKit cache
  делает повторный билд идентичных layers ~30 sec.
- Path-filter оставлен на maven-test (тесты не запускаются на frontend-only PR
  — они бэкендовые) и на docker-admin-ui (frontend-only).

Run: pnpm test → 51 passed.

ordinis-admin-ui/package.json

@@ -6,7 +6,9 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "preview": "vite preview --host 0.0.0.0 --port 4173"
+    "preview": "vite preview --host 0.0.0.0 --port 4173",
+    "test": "vitest run",
+    "test:watch": "vitest"
   },
   "dependencies": {
     "@hookform/resolvers": "^3.9.1",
@@ -32,6 +34,7 @@
     "tailwindcss": "^4.0.0-beta.7",
     "@tailwindcss/vite": "^4.0.0-beta.7",
     "typescript": "^5.7.2",
-    "vite": "^6.0.5"
+    "vite": "^6.0.5",
+    "vitest": "^2.1.9"
   }
 }