Phase 2/3: Employees list/detail + mutation RPCs + action panels

- supabase/functions.sql, functions_2.sql: Postgres RPCs for every
  employee/position/reorg mutation (hire, terminate, transfer, promote,
  start/adjust/return karenz, change data, rehire, create position, staff
  internally, apply/undo reorg). Each resolves manager_id server-side,
  writes history + audit atomically, and enforces hr_admin via
  require_hr_admin() (backed by the existing RLS policy).
- actions/employees.ts, positions.ts, reorg.ts: Server Actions wrapping
  the RPCs, returning success/error for client-side toast handling.
- Employees list (search/filter/pagination) and detail (4 tabs: Stammdaten,
  Vertrag & Gehalt, Organisation, Historie) reading from employees_directory.
- 6 action slide-over panels: Transfer, Promote, Karenz (start/adjust/
  return), Daten aendern (person+contract diffing), Terminate (with direct-
  report reparenting warning + offboarding checklist), Rehire.
- lib/org.ts: shared division/department/team/location lookups.

Verified live: promote mutation updates salary, writes history/audit, and
the detail page reflects it after refresh, no console errors.

Note: the spec's Karenz-verwalten panel only covers employees already on
Karenz; added a start-Karenz mode (Karenzbeginn/geplante Rueckkehr) to
cover the Aktiv-employee case implied by the header button but not
specified in the panel list.

components/employees/tabs/OrganisationTab.tsx

@@ -0,0 +1,59 @@
+import Link from "next/link";
+import { Avatar } from "@/components/ui/Avatar";
+
+type MiniEmployee = { id: string; first_name: string; last_name: string; job_title: string; status?: string };
+
+type OrganisationTabProps = {
+  manager: MiniEmployee | null;
+  directReports: MiniEmployee[];
+  breadcrumb: string;
+};
+
+export function OrganisationTab({ manager, directReports, breadcrumb }: OrganisationTabProps) {
+  return (
+    <div className="flex flex-col gap-6">
+      <div>
+        <h3 className="text-xs font-semibold uppercase tracking-wide text-ink-muted">Organisationseinheit</h3>
+        <p className="mt-1 text-sm text-ink">{breadcrumb}</p>
+      </div>
+
+      <div>
+        <h3 className="mb-2 text-xs font-semibold uppercase tracking-wide text-ink-muted">Führungskraft</h3>
+        {manager ? (
+          <Link href={`/employees/${manager.id}`} className="flex w-fit items-center gap-3 rounded border border-border p-3 hover:bg-surface">
+            <Avatar firstName={manager.first_name} lastName={manager.last_name} />
+            <div>
+              <div className="text-sm font-semibold text-ink">
+                {manager.first_name} {manager.last_name}
+              </div>
+              <div className="text-xs text-ink-muted">{manager.job_title}</div>
+            </div>
+          </Link>
+        ) : (
+          <p className="text-sm text-ink-muted">Keine Führungskraft (Geschäftsführung)</p>
+        )}
+      </div>
+
+      <div>
+        <h3 className="mb-2 text-xs font-semibold uppercase tracking-wide text-ink-muted">Direkte Berichte ({directReports.length})</h3>
+        {directReports.length > 0 ? (
+          <div className="grid grid-cols-1 gap-2 sm:grid-cols-2 lg:grid-cols-3">
+            {directReports.map((r) => (
+              <Link key={r.id} href={`/employees/${r.id}`} className="flex items-center gap-3 rounded border border-border p-3 hover:bg-surface">
+                <Avatar firstName={r.first_name} lastName={r.last_name} />
+                <div>
+                  <div className="text-sm font-semibold text-ink">
+                    {r.first_name} {r.last_name}
+                  </div>
+                  <div className="text-xs text-ink-muted">{r.job_title}</div>
+                </div>
+              </Link>
+            ))}
+          </div>
+        ) : (
+          <p className="text-sm text-ink-muted">Keine direkten Berichte.</p>
+        )}
+      </div>
+    </div>
+  );
+}