Phase 3: Hire wizard, draft resume, and two real SQL bugfixes

- components/hire/: 4-step Hire Wizard (Person/Position/Vertrag/
  Zusammenfassung) matching sec4.4, with a HireWizardProvider context so it
  can be opened both from the global "+ Neueinstellung" button and from a
  "Fortsetzen" link on a saved draft.
- actions/hireDrafts.ts: save/delete hire_drafts (owner-scoped RLS already
  in place from Phase 1). Dashboard now shows the "Entwuerfe" card the
  Phase 1 plan deferred, since the wizard it depends on now exists.
- lib/positions.ts: shared open-positions loader (position number, org
  breadcrumb, resolved manager name) used by both the wizard and (later)
  the Positions page.

Two real bugs found via live testing and fixed in supabase/functions.sql:
1. hire_employee/rehire_employee: a two-branch CASE returning bare string
   literals defaults to `text`, not the target enum, so `status = case
   when ... then 'Geplant' else 'Aktiv' end` failed against the
   employment_status column. Fixed with an explicit ::employment_status
   cast on the whole CASE expression.
2. Postgres precedence gotcha: ->> and || sit at the *same* precedence
   tier and left-associate, so `payload->>'first_name' || ' ' ||
   payload->>'last_name'` does not group the way it reads - it tries to
   apply ->> to an intermediate text value and fails with "operator does
   not exist: text ->> unknown". Fixed by parenthesizing every ->>'...'
   expression that participates in a || chain.

Also fixed: hire_employee referenced v_position.title outside the branch
that assigns v_position, raising "record not assigned" whenever a hire
wasn't tied to a position_id; extracted a v_job_title variable instead.

Verified live end-to-end: wizard search -> select position -> submit
creates the employee, closes the position, and writes matching
employee_history + audit_log rows atomically.

components/hire/StepSummary.tsx

@@ -0,0 +1,56 @@
+import { fmtDate, fmtEUR } from "@/lib/format";
+import type { OpenPositionResolved } from "@/lib/positions";
+import type { HireDraftData } from "./types";
+
+const PAYGRADE_LABELS: Record<string, string> = {
+  A: "A – Einstieg",
+  B: "B – Qualifiziert",
+  C: "C – Erfahren",
+  D: "D – Spezialist:in",
+  E: "E – Teamleitung",
+  F: "F – Bereichsleitung / GF",
+};
+
+type StepSummaryProps = {
+  draft: HireDraftData;
+  selectedPosition: OpenPositionResolved | null;
+  locations: { id: string; name: string; country: string }[];
+};
+
+export function StepSummary({ draft, selectedPosition, locations }: StepSummaryProps) {
+  const location = locations.find((l) => l.id === draft.locationId);
+  const rows: [string, string][] = [
+    ["Name", `${draft.firstName} ${draft.lastName}`],
+    ["Geschlecht", draft.gender === "m" ? "männlich" : "weiblich"],
+    ["Geburtsdatum", fmtDate(draft.birthDate)],
+    ["SV-Nummer", draft.svNummer || "–"],
+    ["E-Mail (privat)", draft.email || "–"],
+    ["Telefon", draft.phone || "–"],
+    ["Standort", location ? `${location.name} (${location.country})` : "–"],
+    ["Position", selectedPosition ? `${selectedPosition.title} (${selectedPosition.position_number})` : "–"],
+    ["Organisationseinheit", selectedPosition?.orgLabel ?? "–"],
+    ["Führungskraft", selectedPosition?.managerName ?? "–"],
+    ["Besetzung", draft.besetzung],
+    ["Eintrittsdatum", fmtDate(draft.entryDate)],
+    ["Vertragsart", draft.contractType === "befristet" ? `befristet bis ${fmtDate(draft.contractEndDate)}` : "unbefristet"],
+    ["Beschäftigungsausmaß", `${draft.employmentType} (${draft.weeklyHours} h)`],
+    ["Bruttogehalt (14x/Jahr)", fmtEUR(Number(draft.salary))],
+    ["Paygrade", PAYGRADE_LABELS[draft.paygrade]],
+  ];
+
+  return (
+    <div className="flex flex-col gap-4">
+      <dl className="grid grid-cols-2 gap-x-6 gap-y-3">
+        {rows.map(([label, value]) => (
+          <div key={label}>
+            <dt className="text-xs font-semibold uppercase tracking-wide text-ink-muted">{label}</dt>
+            <dd className="mt-0.5 text-sm text-ink">{value}</dd>
+          </div>
+        ))}
+      </dl>
+      <p className="rounded bg-info-bg px-3 py-2 text-sm text-info-text">
+        Personalnummer und Firmen-E-Mail-Adresse werden automatisch vergeben.
+      </p>
+    </div>
+  );
+}