Add automated tests for audit log readable summaries

Original task: add unit tests for the new `formatAuditSummary` formatter
and an API-level test asserting the enriched group sub-resource audit
metadata, and wire both into the existing `test` workflow.

What changed:
- Extracted `formatAuditSummary` and its helpers (`asRecord`, `asString`,
  `asNumber`, `unitLabel`, `appName`, `linkedAppName`, `plainName`,
  `changeCount`) out of `artifacts/tx-os/src/pages/admin.tsx` into a new
  `artifacts/tx-os/src/lib/audit-summary.ts` module so the pure formatter
  can be unit-tested without the React tree. `admin.tsx` now imports the
  helpers from that module.
- Added `artifacts/tx-os/src/__tests__/audit-summary.test.mjs` with 22
  Node test-runner cases covering app rename (EN + AR), app-update
  fallback, group rename, group multi-field update, registration toggle
  (open / close / with-other-changes), and every group.user/app/role
  add/remove name vs id-only branch, plus the unknown-action default.
- Added `pnpm --filter @workspace/tx-os test` (Node 24's native
  TypeScript loader runs the .mjs tests against the .ts module directly).
- Added `artifacts/api-server/tests/group-audit-metadata.test.mjs` using
  the same harness as `groups-crud.test.mjs`. It hits POST/DELETE
  `/api/groups/:id/{users,apps,roles}/:targetId` and reads the resulting
  `audit_logs.metadata`, asserting `username`, `appSlug` /`appNameEn` /
  `appNameAr`, and `roleName` are persisted alongside the raw IDs.
- Updated the `test` workflow to run the tx-os unit tests before the
  api-server tests, then the tx-os e2e tests.

Verification: all 22 tx-os unit tests pass via the new pnpm script, and
all 6 new api-server audit-metadata tests pass against a live server.
The overall api-server suite still has pre-existing flakes
(executive-meetings notifications/status transitions, and the
count-based group invariant in groups-crud.test.mjs) that are unrelated
to this change; both flake clusters are filed as follow-up tasks.

artifacts/tx-os/package.json

@@ -8,6 +8,7 @@
     "build": "vite build --config vite.config.ts",
     "serve": "vite preview --config vite.config.ts --host 0.0.0.0",
     "typecheck": "tsc -p tsconfig.json --noEmit",
+    "test": "node --test 'src/__tests__/**/*.test.mjs'",
     "test:e2e": "playwright test --config playwright.config.mjs"
   },
   "devDependencies": {