Module tasks + knowledgecenter_update aus Kundenprojekt übernehmen (bereinigt)

Beide Module wurden aus einem anderen Kundenprojekt kopiert und bereinigt:

Knowledgecenter:
- Bild-Cache (1.985 Dateien) geleert, Ordnerstruktur mit .gitkeep behalten
- Files-Gallery-Lizenzschlüssel entfernt (config.php)
- Kundenspezifische Kategorien gelöscht: Teil I/II/III QM-Struktur,
  nummerierte QM-Kapitel, Gremien (Präsidium/Finanzausschuss/Landesausschuss),
  Sitzungsservice-Serie, Protokoll-Abteilungen, Testeinträge
- 56 generische Kategorien bleiben (Downloads, Onboarding, Personalthemen …)

Tasks:
- Alle Betriebsdaten gelöscht (114 Tasks, 914 Submissions, 579 Assignments)
- Task-Definitionen und Verlinkungen geleert
- Kategoriestruktur bleibt (Allgemein, IT, Personal, Buchhaltung …)

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

module/tasks/lib/Db.php

@@ -0,0 +1,159 @@
+<?php
+declare(strict_types=1);
+
+class TaskCertDb
+{
+    public static function conn(): mysqli
+    {
+        if (!isset($GLOBALS['mysql_con']) || !($GLOBALS['mysql_con'] instanceof mysqli)) {
+            throw new RuntimeException('task_cert: Missing mysqli connection in $GLOBALS["mysql_con"].');
+        }
+
+        return $GLOBALS['mysql_con'];
+    }
+
+    public static function beginTransaction(): void
+    {
+        mysqli_begin_transaction(self::conn());
+    }
+
+    public static function commit(): void
+    {
+        mysqli_commit(self::conn());
+    }
+
+    public static function rollback(): void
+    {
+        mysqli_rollback(self::conn());
+    }
+
+    public static function fetchAll(string $sql, string $types = '', array $params = []): array
+    {
+        if ($types === '' && $params === []) {
+            $result = mysqli_query(self::conn(), $sql);
+            if ($result === false) {
+                throw new RuntimeException('task_cert query failed: ' . mysqli_error(self::conn()));
+            }
+
+            if ($result instanceof mysqli_result) {
+                $rows = mysqli_fetch_all($result, MYSQLI_ASSOC);
+                mysqli_free_result($result);
+                return $rows;
+            }
+
+            return [];
+        }
+
+        $stmt = self::prepareAndBind($sql, $types, $params);
+        mysqli_stmt_execute($stmt);
+        $result = mysqli_stmt_get_result($stmt);
+
+        if ($result === false) {
+            $error = mysqli_stmt_error($stmt);
+            mysqli_stmt_close($stmt);
+            throw new RuntimeException('task_cert fetchAll failed: ' . $error);
+        }
+
+        $rows = mysqli_fetch_all($result, MYSQLI_ASSOC);
+        mysqli_free_result($result);
+        mysqli_stmt_close($stmt);
+
+        return $rows;
+    }
+
+    public static function fetchOne(string $sql, string $types = '', array $params = []): ?array
+    {
+        $rows = self::fetchAll($sql, $types, $params);
+        if ($rows === []) {
+            return null;
+        }
+
+        return $rows[0];
+    }
+
+    public static function scalar(string $sql, string $types = '', array $params = [])
+    {
+        $row = self::fetchOne($sql, $types, $params);
+        if ($row === null) {
+            return null;
+        }
+
+        foreach ($row as $value) {
+            return $value;
+        }
+
+        return null;
+    }
+
+    public static function execute(string $sql, string $types = '', array $params = []): int
+    {
+        if ($types === '' && $params === []) {
+            $ok = mysqli_query(self::conn(), $sql);
+            if ($ok === false) {
+                throw new RuntimeException('task_cert execute failed: ' . mysqli_error(self::conn()));
+            }
+
+            return mysqli_affected_rows(self::conn());
+        }
+
+        $stmt = self::prepareAndBind($sql, $types, $params);
+        mysqli_stmt_execute($stmt);
+        $affected = mysqli_stmt_affected_rows($stmt);
+        $error = mysqli_stmt_error($stmt);
+        mysqli_stmt_close($stmt);
+
+        if ($error !== '') {
+            throw new RuntimeException('task_cert execute failed: ' . $error);
+        }
+
+        return $affected;
+    }
+
+    public static function insert(string $sql, string $types, array $params): int
+    {
+        $stmt = self::prepareAndBind($sql, $types, $params);
+        mysqli_stmt_execute($stmt);
+        $error = mysqli_stmt_error($stmt);
+        mysqli_stmt_close($stmt);
+
+        if ($error !== '') {
+            throw new RuntimeException('task_cert insert failed: ' . $error);
+        }
+
+        return (int) mysqli_insert_id(self::conn());
+    }
+
+    private static function prepareAndBind(string $sql, string $types, array $params): mysqli_stmt
+    {
+        $stmt = mysqli_prepare(self::conn(), $sql);
+        if (!$stmt) {
+            throw new RuntimeException('task_cert prepare failed: ' . mysqli_error(self::conn()));
+        }
+
+        self::bindParams($stmt, $types, $params);
+
+        return $stmt;
+    }
+
+    private static function bindParams(mysqli_stmt $stmt, string $types, array $params): void
+    {
+        if ($types === '') {
+            return;
+        }
+
+        $params = array_values($params);
+        if (strlen($types) !== count($params)) {
+            throw new InvalidArgumentException('task_cert bind mismatch: number of types != number of params');
+        }
+
+        $bindValues = [$types];
+        foreach ($params as $index => $value) {
+            $bindValues[] = &$params[$index];
+        }
+
+        $ok = call_user_func_array([$stmt, 'bind_param'], $bindValues);
+        if ($ok === false) {
+            throw new RuntimeException('task_cert bind_param failed: ' . mysqli_stmt_error($stmt));
+        }
+    }
+}