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/StepPerson.tsx

@@ -0,0 +1,66 @@
+import type { HireDraftData } from "./types";
+
+type StepPersonProps = {
+  draft: HireDraftData;
+  update: (patch: Partial<HireDraftData>) => void;
+  locations: { id: string; name: string; country: string }[];
+};
+
+export function StepPerson({ draft, update, locations }: StepPersonProps) {
+  return (
+    <div className="flex flex-col gap-4">
+      <div className="grid grid-cols-2 gap-3">
+        <div>
+          <label className="mb-1 block text-sm font-semibold text-ink">Vorname*</label>
+          <input value={draft.firstName} onChange={(e) => update({ firstName: e.target.value })} className="w-full rounded border border-border px-3 py-2 text-sm" />
+        </div>
+        <div>
+          <label className="mb-1 block text-sm font-semibold text-ink">Nachname*</label>
+          <input value={draft.lastName} onChange={(e) => update({ lastName: e.target.value })} className="w-full rounded border border-border px-3 py-2 text-sm" />
+        </div>
+      </div>
+      <div className="grid grid-cols-2 gap-3">
+        <div>
+          <label className="mb-1 block text-sm font-semibold text-ink">Geschlecht*</label>
+          <select
+            value={draft.gender}
+            onChange={(e) => update({ gender: e.target.value as HireDraftData["gender"] })}
+            className="w-full rounded border border-border px-3 py-2 text-sm"
+          >
+            <option value="m">männlich</option>
+            <option value="w">weiblich</option>
+          </select>
+        </div>
+        <div>
+          <label className="mb-1 block text-sm font-semibold text-ink">Geburtsdatum*</label>
+          <input type="date" value={draft.birthDate} onChange={(e) => update({ birthDate: e.target.value })} className="w-full rounded border border-border px-3 py-2 text-sm" />
+        </div>
+      </div>
+      <div>
+        <label className="mb-1 block text-sm font-semibold text-ink">SV-Nummer</label>
+        <input value={draft.svNummer} onChange={(e) => update({ svNummer: e.target.value })} className="w-full rounded border border-border px-3 py-2 text-sm" />
+      </div>
+      <div className="grid grid-cols-2 gap-3">
+        <div>
+          <label className="mb-1 block text-sm font-semibold text-ink">E-Mail (privat)</label>
+          <input type="email" value={draft.email} onChange={(e) => update({ email: e.target.value })} className="w-full rounded border border-border px-3 py-2 text-sm" />
+        </div>
+        <div>
+          <label className="mb-1 block text-sm font-semibold text-ink">Telefon</label>
+          <input value={draft.phone} onChange={(e) => update({ phone: e.target.value })} className="w-full rounded border border-border px-3 py-2 text-sm" />
+        </div>
+      </div>
+      <div>
+        <label className="mb-1 block text-sm font-semibold text-ink">Standort*</label>
+        <select value={draft.locationId} onChange={(e) => update({ locationId: e.target.value })} className="w-full rounded border border-border px-3 py-2 text-sm">
+          <option value="">Bitte wählen…</option>
+          {locations.map((l) => (
+            <option key={l.id} value={l.id}>
+              {l.name} ({l.country})
+            </option>
+          ))}
+        </select>
+      </div>
+    </div>
+  );
+}