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.

app/(app)/page.tsx

@@ -1,4 +1,5 @@
 import Link from "next/link";
+import { DraftsCard } from "@/components/dashboard/DraftsCard";
 import { actionBadgeStyle } from "@/lib/colors";
 import { fmtDate } from "@/lib/format";
 import { createClient } from "@/lib/supabase/server";
@@ -33,6 +34,16 @@ const KIND_LABEL = { hire: "Eintritt", exit: "Austritt", return: "Karenz-Rückke
 
 export default async function DashboardPage() {
   const supabase = await createClient();
+  const {
+    data: { user },
+  } = await supabase.auth.getUser();
+  const { data: drafts } = user
+    ? await supabase
+        .from("hire_drafts")
+        .select("id, step, payload, updated_at")
+        .eq("created_by", user.id)
+        .order("updated_at", { ascending: false })
+    : { data: [] };
 
   const today = new Date();
   const todayIso = isoDate(today);
@@ -152,6 +163,7 @@ export default async function DashboardPage() {
 
   return (
     <div className="flex flex-col gap-6">
+      {drafts && drafts.length > 0 && <DraftsCard drafts={drafts} />}
       <div className="grid grid-cols-2 gap-4 sm:grid-cols-3 lg:grid-cols-6">
         {kpis.map((kpi) => (
           <div key={kpi.label} className="rounded border border-border bg-white p-4">