Org assignment history, mobile support, and a correctness pass

Data model
- employee_assignments records org placement over time (valid_from/valid_to),
  written by a trigger on `employees` rather than inside each RPC: ~70
  `update employees` statements spread over fifteen migrations mean per-call
  bookkeeping would miss paths today and again with every future RPC. A
  partial unique index enforces the one-open-interval invariant the trigger
  relies on when closing the current row.
- The Organigramm gains a Stichtag (default today). Membership comes from
  entry/exit/karenz, past placement from the new history, future placement
  projected from pending_org_changes. Placements predating the migration are
  backfilled with today's values and flagged as such in the UI, since
  employee_history only ever stored free text and cannot be reconstructed.

Correctness
- Reports and exports silently truncated at PostgREST's 1000-row cap
  (db.max_rows); employee_history is already past it at ~800 staff. Every
  whole-table read now pages explicitly.
- XLSX date cells were a day early: ExcelJS converts a Date to an Excel
  serial straight off getTime(), so a Date built at local midnight lands on
  the previous day's serial in any positive-offset zone.
- Date handling is pinned to Europe/Vienna throughout, and date-only strings
  are formatted without a Date round-trip. The dashboard's YTD window was
  built by round-tripping a local Date through toISOString(), which shifted
  it a day early and dropped 31 December entirely.
- Export routes parsed measure/group/split/eventType with unchecked `as`
  casts, so an unknown value reached column headers as `undefined` and the
  Content-Disposition filename. Parsed against the label maps now, with the
  filename slugged as a backstop.
- toXlsx keyed columns by header text, silently dropping the second of any
  two columns sharing a name — split columns take their header from data.
- The org chart tree walks had no cycle guard; nothing in the schema forbids
  a manager_id cycle, and one would hang the tab rather than misreport.
- The login page reflected ?error= verbatim, letting anyone put arbitrary
  text on the real sign-in screen; messages are looked up by code now.
- React Flow needs elementsSelectable on, or it sets pointer-events:none on
  the whole node and the expand control stops responding.

UI
- Mobile: the shell was unusable below lg — a fixed 236px margin pushed
  content off-screen with no mobile navigation at all. The sidebar is now a
  drawer, dvh replaces vh, safe-area insets are honoured, inputs are 16px so
  iOS stops zooming on focus, and form grids stack.
- Org chart nodes redesigned: per-kind accent stripes and icons, vacant
  roles called out, expand control moved to the bottom edge carrying the
  child count.
- Pagination is windowed; it previously rendered one link per page (54 for
  the employee list, unbounded for the audit log).
- Positions page reduced to open positions with a single "Besetzen" action.
- The employee Organisation tab links into the org chart focused on that
  person, reusing the chart's existing search-match highlighting.

Also included, uncommitted until now
- Dependants, HR notes, academic titles, split address fields, position
  validity and role/employment fields, with their migrations and UI.
- Docker/compose deployment setup, data-model and security-review docs.

components/ui/Modal.tsx

@@ -25,21 +25,27 @@ export function Modal({ open, onClose, title, children, footer, widthClassName =
   if (!open) return null;
 
   return (
-    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/40 p-4">
-      <div className={`flex max-h-[85vh] w-full flex-col rounded bg-white shadow-xl ${widthClassName}`}>
-        <div className="flex items-center justify-between border-b border-border px-6 py-4">
+    // Bottom-aligned on a phone (thumb reach, and it clears the keyboard when
+    // a field is focused), centred from sm up.
+    <div className="fixed inset-0 z-50 flex items-end justify-center bg-black/40 p-0 sm:items-center sm:p-4">
+      <div
+        role="dialog"
+        aria-modal="true"
+        aria-label={title}
+        className={`flex max-h-[92dvh] w-full flex-col rounded-t-xl bg-white shadow-xl sm:max-h-[85dvh] sm:rounded ${widthClassName}`}
+      >
+        <div className="flex shrink-0 items-center justify-between border-b border-border px-4 py-3 sm:px-6 sm:py-4">
           <h2 className="text-lg font-bold text-ink">{title}</h2>
-          <button
-            type="button"
-            onClick={onClose}
-            aria-label="Schließen"
-            className="rounded p-1 text-ink-muted hover:bg-surface"
-          >
+          <button type="button" onClick={onClose} aria-label="Schließen" className="-mr-1 rounded p-2 text-ink-muted hover:bg-surface">
             <X className="h-5 w-5" />
           </button>
         </div>
-        <div className="flex-1 overflow-y-auto px-6 py-4">{children}</div>
-        {footer && <div className="flex items-center justify-end gap-2 border-t border-border px-6 py-4">{footer}</div>}
+        <div className="flex-1 overflow-y-auto overscroll-contain px-4 py-4 sm:px-6">{children}</div>
+        {footer && (
+          <div className="flex shrink-0 flex-wrap items-center justify-end gap-2 border-t border-border px-4 py-3 pb-[max(0.75rem,env(safe-area-inset-bottom))] sm:px-6 sm:py-4">
+            {footer}
+          </div>
+        )}
       </div>
     </div>
   );

components/ui/Pagination.tsx

@@ -0,0 +1,57 @@
+import Link from "next/link";
+
+// Shared by the employee list and the audit log, which both used to render
+// one link per page: 54 of them for ~800 employees, and an unbounded number
+// for the audit log, all in a single overflowing row. This shows the first
+// and last page plus a window around the current one, with the gaps elided.
+const WINDOW = 2;
+
+function pageItems(current: number, total: number): number[] {
+  const pages = new Set<number>([1, total]);
+  for (let p = current - WINDOW; p <= current + WINDOW; p++) {
+    if (p >= 1 && p <= total) pages.add(p);
+  }
+  return [...pages].sort((a, b) => a - b);
+}
+
+type PaginationProps = {
+  page: number;
+  totalPages: number;
+  hrefFor: (page: number) => string;
+  /** Screen-reader name, e.g. "Mitarbeiter:innen" — several lists per app. */
+  label: string;
+};
+
+export function Pagination({ page, totalPages, hrefFor, label }: PaginationProps) {
+  if (totalPages <= 1) return null;
+
+  const current = Math.min(Math.max(1, page), totalPages);
+  const items = pageItems(current, totalPages);
+
+  return (
+    <nav aria-label={`Seiten – ${label}`} className="flex flex-wrap items-center justify-center gap-1 text-sm">
+      {current > 1 && (
+        <Link href={hrefFor(current - 1)} rel="prev" className="rounded px-3 py-1 font-semibold text-ink-body hover:bg-surface">
+          Zurück
+        </Link>
+      )}
+      {items.map((p, i) => (
+        <span key={p} className="flex items-center gap-1">
+          {i > 0 && p - items[i - 1] > 1 && <span className="px-1 text-ink-muted">…</span>}
+          <Link
+            href={hrefFor(p)}
+            aria-current={p === current ? "page" : undefined}
+            className={`rounded px-3 py-1 ${p === current ? "bg-brand-500 font-semibold text-white" : "text-ink-body hover:bg-surface"}`}
+          >
+            {p}
+          </Link>
+        </span>
+      ))}
+      {current < totalPages && (
+        <Link href={hrefFor(current + 1)} rel="next" className="rounded px-3 py-1 font-semibold text-ink-body hover:bg-surface">
+          Weiter
+        </Link>
+      )}
+    </nav>
+  );
+}

components/ui/Picklist.tsx

@@ -0,0 +1,60 @@
+"use client";
+
+import { X } from "lucide-react";
+
+// Dropdown-to-add, chip-to-remove multi-select for short, fixed option
+// lists (no search needed) — e.g. academic titles. The dropdown only offers
+// options not yet picked; the reset key forces the <select> back to its
+// placeholder after each pick instead of showing the just-added option.
+export function Picklist({
+  options,
+  value,
+  onChange,
+  placeholder = "Hinzufügen…",
+}: {
+  options: string[];
+  value: string[];
+  onChange: (value: string[]) => void;
+  placeholder?: string;
+}) {
+  const available = options.filter((o) => !value.includes(o));
+
+  function remove(option: string) {
+    onChange(value.filter((v) => v !== option));
+  }
+
+  return (
+    <div className="flex flex-col gap-2">
+      <select
+        key={value.length}
+        defaultValue=""
+        onChange={(e) => {
+          if (e.target.value) onChange([...value, e.target.value]);
+        }}
+        disabled={available.length === 0}
+        className="w-full rounded border border-border px-3 py-2 text-sm disabled:bg-surface disabled:text-ink-muted"
+      >
+        <option value="" disabled>
+          {available.length > 0 ? placeholder : "Alle Optionen ausgewählt"}
+        </option>
+        {available.map((o) => (
+          <option key={o} value={o}>
+            {o}
+          </option>
+        ))}
+      </select>
+      {value.length > 0 && (
+        <div className="flex flex-wrap gap-1.5">
+          {value.map((v) => (
+            <span key={v} className="flex items-center gap-1 rounded-full bg-brand-500 px-3 py-1.5 text-xs font-semibold text-white">
+              {v}
+              <button type="button" onClick={() => remove(v)} aria-label={`${v} entfernen`} className="text-white/80 hover:text-white">
+                <X className="h-3 w-3" />
+              </button>
+            </span>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}

components/ui/SlideOver.tsx

@@ -29,26 +29,28 @@ export function SlideOver({ open, onClose, title, subtitle, children, footer }:
         onClick={onClose}
       />
       <div
-        className={`absolute right-0 top-0 flex h-full w-full max-w-md flex-col bg-white shadow-xl transition-transform duration-200 ${
+        role="dialog"
+        aria-modal="true"
+        aria-label={title}
+        className={`absolute right-0 top-0 flex h-dvh w-full max-w-md flex-col bg-white shadow-xl transition-transform duration-200 ${
           open ? "translate-x-0" : "translate-x-full"
         }`}
       >
-        <div className="flex items-start justify-between border-b border-border px-6 py-4">
-          <div>
+        <div className="flex shrink-0 items-start justify-between border-b border-border px-4 py-3 pt-[max(0.75rem,env(safe-area-inset-top))] sm:px-6 sm:py-4">
+          <div className="min-w-0">
             <h2 className="text-lg font-bold text-ink">{title}</h2>
-            {subtitle && <p className="text-sm text-ink-muted">{subtitle}</p>}
+            {subtitle && <p className="truncate text-sm text-ink-muted">{subtitle}</p>}
           </div>
-          <button
-            type="button"
-            onClick={onClose}
-            aria-label="Schließen"
-            className="rounded p-1 text-ink-muted hover:bg-surface"
-          >
+          <button type="button" onClick={onClose} aria-label="Schließen" className="-mr-1 rounded p-2 text-ink-muted hover:bg-surface">
             <X className="h-5 w-5" />
           </button>
         </div>
-        <div className="flex-1 overflow-y-auto px-6 py-4">{children}</div>
-        {footer && <div className="flex items-center justify-end gap-2 border-t border-border px-6 py-4">{footer}</div>}
+        <div className="flex-1 overflow-y-auto overscroll-contain px-4 py-4 sm:px-6">{children}</div>
+        {footer && (
+          <div className="flex shrink-0 flex-wrap items-center justify-end gap-2 border-t border-border px-4 py-3 pb-[max(0.75rem,env(safe-area-inset-bottom))] sm:px-6 sm:py-4">
+            {footer}
+          </div>
+        )}
       </div>
     </div>
   );

components/ui/Toast.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { createContext, useCallback, useContext, useState, type ReactNode } from "react";
+import { createContext, useCallback, useContext, useMemo, useState, type ReactNode } from "react";
 
 type ToastVariant = "success" | "error" | "info";
 type ToastItem = { id: number; message: string; variant: ToastVariant };
@@ -23,8 +23,13 @@ export function ToastProvider({ children }: { children: ReactNode }) {
     setTimeout(() => setToasts((prev) => prev.filter((t) => t.id !== id)), 4000);
   }, []);
 
+  // This provider wraps the whole app, so an inline object literal here would
+  // hand every consumer a new context value on each toast and re-render the
+  // entire tree for a 4-second banner.
+  const value = useMemo(() => ({ showToast }), [showToast]);
+
   return (
-    <ToastContext.Provider value={{ showToast }}>
+    <ToastContext.Provider value={value}>
       {children}
       <div className="pointer-events-none fixed bottom-4 right-4 z-[100] flex flex-col gap-2">
         {toasts.map((t) => (