Reorganize into monorepo layout, move mitarbeiter-app to legacy reference

Consolidates the previously separate omsorgapp and omsorgCore repos
(each had their own nested .git with GitHub history) plus the old
root-level website/mitarbeiter-app into a single monorepo, matching
the structure already documented in the root CLAUDE.md. Also moves
the PHP employee app aside as omsorgWeb/mitarbeiter-app-legacy/ to
serve as a template for a ground-up rewrite.

Fixes .gitignore in the same pass: the config-secrets/uploads/data
patterns were unanchored (relative to repo root, not depth-agnostic),
so they silently stopped matching once the app moved under omsorgWeb/.
Patterns are now **/-prefixed and cover both mitarbeiter-app and
mitarbeiter-app-legacy, keeping DB/SMTP credentials and uploaded
employee documents out of version control.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

omsorgWeb/mitarbeiter-app-legacy/actions/delete-dokument.php

@@ -0,0 +1,42 @@
+<?php
+require_once __DIR__ . '/../lib/auth.php';
+require_login();
+
+if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
+    header('Location: ../pages/dokumentenarchiv.php');
+    exit;
+}
+
+$id = (int) ($_POST['id'] ?? 0);
+if ($id <= 0) {
+    http_response_code(400);
+    echo 'Ungültige Anfrage.';
+    exit;
+}
+
+$stmt = db()->prepare('SELECT * FROM dokumente WHERE id = ?');
+$stmt->execute([$id]);
+$doc = $stmt->fetch();
+
+if (!$doc) {
+    http_response_code(404);
+    echo 'Dokument nicht gefunden.';
+    exit;
+}
+
+$user = current_user();
+if ((int) $doc['user_id'] !== (int) $user['id'] && !is_admin()) {
+    http_response_code(403);
+    echo 'Keine Berechtigung.';
+    exit;
+}
+
+$file_path = dirname(__DIR__) . '/uploads/' . $doc['filename'];
+if (is_file($file_path)) {
+    unlink($file_path);
+}
+
+db()->prepare('DELETE FROM dokumente WHERE id = ?')->execute([$id]);
+
+header('Location: ../pages/dokumentenarchiv.php?deleted=1');
+exit;