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).

actions/positions.ts

@@ -9,7 +9,7 @@ type ActionResult = { success: boolean; error?: string };
 const POSITION_PATHS = ["/positions", "/orgchart", "/"];
 
 async function callRpc(
-  fn: "create_position" | "delete_position" | "staff_position_internally",
+  fn: "create_position" | "delete_position",
   payload: Record<string, unknown>,
   revalidate: string[]
 ): Promise<ActionResult> {
@@ -34,13 +34,6 @@ export async function deletePosition(positionId: string): Promise<ActionResult>
   return callRpc("delete_position", { position_id: positionId }, POSITION_PATHS);
 }
 
-export async function staffPositionInternally(payload: {
-  position_id: string;
-  employee_id: string;
-}): Promise<ActionResult> {
-  return callRpc("staff_position_internally", payload, [...POSITION_PATHS, "/employees", `/employees/${payload.employee_id}`]);
-}
-
 export type SuperiorSearchResult = { id: string; first_name: string; last_name: string; job_title: string; division_id: string };
 
 // For "Position ausschreiben": superior lookup, filtered to team-leads when