SVNR validation, CI, and a dependency/security pass

Positions
- Removed the "Besetzen" action, the StaffInternallyModal behind it and the
  now-unreachable staffPositionInternally server action: a position is filled
  through the hire process, not from the positions list. Note that
  transfer_employee has no position_id at all and never touched `positions`,
  so with staff_position_internally out of the UI, hire_employee is the only
  thing that closes a position — a transfer into an open one leaves it open.
  The RPC itself is still in the database and still covered by its tests.

SVNR
- Austrian social security numbers are now validated: ten digits, weighted
  check digit mod 11, and the TTMMJJ tail cross-checked against birth_date,
  which is what catches a transposed date that a valid check digit would let
  through. A serial whose weighted sum lands on 11 is rejected rather than
  wrapped — those are never issued.
- Applies to Austrian locations only; the German/Czech/Slovenian equivalents
  have their own formats and stay free-form.
- Enforced by a trigger, not inside hire_employee/change_employee_data, for
  the same reason as the assignment history: both have been redefined by
  half a dozen migrations. Only a *newly written* value is checked, so a
  legacy number never blocks an unrelated transfer or address change.
- The seed drew a random four-digit prefix, so its check digit was right
  only by chance and every seeded Austrian row would now be rejected;
  it computes the check digit properly now.

Tech stack
- next 16.2.11 closes nine advisories against 16.2.10, including a
  middleware/proxy bypass in App Router apps on Turbopack — proxy.ts is this
  app's entry gate. RLS remains the real boundary, so the blast radius was a
  blank page rather than data, but it is a patch-level fix. Also react
  19.2.8, tailwind 4.3.3, lucide-react 1.26, supabase-js/ssr, postcss.
- CI runs lint, typecheck, schema/type drift, tests and build; a second job
  replays every migration onto an empty database and runs the integration
  suite against it, so a migration that cannot be replayed from scratch
  fails here instead of during a restore.
- scripts/check-schema-types.mjs diffs the hand-written lib/supabase/types.ts
  against the migrations. Reading the SQL rather than a live database keeps
  Postgres out of the fast CI job. Verified in both directions.
- vitest now runs two projects: node for logic, jsdom for components. The
  first component test covers the org chart expand control, which broke
  earlier this session when elementsSelectable={false} made React Flow
  compute pointer-events:none for the whole node; re-introducing that prop
  fails three of these tests.
- Content-Security-Policy is emitted report-only. Enforcing a policy derived
  from inspection rather than from violation reports risks blanking the app;
  'unsafe-inline' on script-src is required until a nonce is threaded through
  proxy.ts, which is a separate change.
- Fixed supabase/seed.ts, which this session's SVNR change had broken: the
  extensionless "../lib/svnr" import does not resolve under Node's ESM
  loader, so the seed failed at startup.
- engines pinned to node >=22 <25, tsconfig target ES2022, and the dead
  test:e2e script removed (no Playwright is installed).

.github/workflows/ci.yml

@@ -0,0 +1,90 @@
+name: CI
+
+on:
+  push:
+    branches: [master, main]
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  check:
+    name: Lint, Typen, Tests, Build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+
+      - run: npm ci
+
+      - name: Lint
+        run: npm run lint
+
+      - name: Typecheck
+        run: npm run typecheck
+
+      # Catches the drift that `tsc` cannot: lib/supabase/types.ts is
+      # hand-written, so a migration adding a column leaves it silently stale.
+      - name: Schema/Typen-Abgleich
+        run: npm run types:check
+
+      - name: Unit- und Komponententests
+        run: npm test
+
+      - name: Build
+        run: npm run build
+        env:
+          # Read at module scope by the Supabase browser client, so the build
+          # needs them present — never the real project's values.
+          NEXT_PUBLIC_SUPABASE_URL: http://127.0.0.1:54321
+          NEXT_PUBLIC_SUPABASE_ANON_KEY: build-time-placeholder
+
+  integration:
+    name: Integrationstests (echtes Postgres)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: npm
+
+      - run: npm ci
+
+      - uses: supabase/setup-cli@v1
+        with:
+          version: latest
+
+      # Applies every migration to a fresh database — which also means a
+      # migration that cannot be replayed from scratch fails here rather than
+      # on a restore or a new environment.
+      - name: Supabase starten
+        run: supabase start
+
+      # `-o env` emits API_URL / ANON_KEY / SERVICE_ROLE_KEY; the app expects
+      # them under its own names.
+      - name: Testumgebung schreiben
+        run: |
+          supabase status -o env \
+            --override-name api.url=NEXT_PUBLIC_SUPABASE_URL \
+            --override-name auth.anon_key=NEXT_PUBLIC_SUPABASE_ANON_KEY \
+            --override-name auth.service_role_key=SUPABASE_SERVICE_ROLE_KEY \
+            | grep -E '^(NEXT_PUBLIC_SUPABASE_URL|NEXT_PUBLIC_SUPABASE_ANON_KEY|SUPABASE_SERVICE_ROLE_KEY)=' \
+            | tr -d '"' > .env.test.local
+
+      - name: Seed
+        run: node --env-file=.env.test.local supabase/seed.ts
+
+      - name: Integrationstests
+        run: npm run test:integration
+
+      - name: Supabase-Logs bei Fehlschlag
+        if: failure()
+        run: supabase status && docker ps -a