add composer-unused, comprehensive docs, and project restructure

- Add icanhazstring/composer-unused as dev dependency for dependency hygiene checks
- Add German documentation (docs/) covering architecture, conventions, workflows, and developer checklists
- Add API layer (ApiAuth, ApiBootstrap, ApiResponse), audit, scheduler, custom fields, and SSO services
- Add Microsoft OIDC SSO, API token management, and user lifecycle features
- Add swagger-ui vendor integration and OpenAPI spec
- Add production Docker setup and bin/ scripts
- Update composer dependencies, config, templates, and frontend assets throughout

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bin/scheduler-run.php

@@ -0,0 +1,39 @@
+#!/usr/bin/env php
+<?php
+
+declare(strict_types=1);
+
+chdir(__DIR__ . '/..');
+
+require 'vendor/autoload.php';
+require 'config/config.php';
+require 'lib/Support/helpers.php';
+
+use MintyPHP\DB;
+use MintyPHP\Service\Scheduler\SchedulerRunService;
+
+$exitCode = 0;
+try {
+    $result = SchedulerRunService::runDueJobs();
+    if (!($result['ok'] ?? false)) {
+        $error = (string) ($result['error'] ?? 'unexpected_error');
+        fwrite(STDERR, sprintf("scheduler run failed: %s\n", $error));
+        $exitCode = 1;
+    } else {
+        $line = sprintf(
+            "scheduler completed: processed=%d success=%d failed=%d skipped=%d duration_ms=%d\n",
+            (int) ($result['processed'] ?? 0),
+            (int) ($result['success'] ?? 0),
+            (int) ($result['failed'] ?? 0),
+            (int) ($result['skipped'] ?? 0),
+            (int) ($result['duration_ms'] ?? 0)
+        );
+        fwrite(STDOUT, $line);
+    }
+} catch (Throwable $exception) {
+    fwrite(STDERR, sprintf("scheduler run failed: unexpected_error: %s\n", $exception->getMessage()));
+    $exitCode = 1;
+} finally {
+    DB::close();
+}
+exit($exitCode);