Backend module: CSV import for the VITEC domain models

New "VITEC Import" module under Web: one import page per domain model
(v1: Market, Solution, Product - registry-driven, adding a model is one
config entry). Workflow: upload a CSV (delimiter and encoding are
auto-detected, including German-Excel semicolon/Windows-1252), map CSV
columns to DB fields, persist the mapping per model together with the
identity field used for matching (new table tx_vitec_import_mapping,
no TCA - pure tool configuration), review a unified list of CSV rows
matched against the DB records (new / update with differing fields /
unchanged / db-only), then apply the checked rows through DataHandler.

Each importable row carries an editable JSON payload textarea - what
is written is the textarea content, not the raw CSV, so editors can
fix values right in the review step. The parsed CSV travels through
the form as a hidden JSON field: no session state, no temp files.
Importable fields are derived from TCA at runtime (scalar types only;
files, categories and other relations are excluded - a flat CSV
cannot carry them). Payloads are whitelisted against that field list
on apply; new records require a storage pid (prefilled from existing
records). BE user permissions apply via DataHandler.

Deliberately out of v1: import log with three-way compare (protection
against overwriting manual edits), images/relations, multiple saved
mappings per model.

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

packages/vitec/Classes/Import/CsvReader.php

@@ -0,0 +1,78 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Evomedien\Vitec\Import;
+
+/**
+ * Tolerant CSV parser for editor-supplied files.
+ *
+ * German Excel exports ship with semicolon delimiters and Windows-1252
+ * encoding; other tools use comma/UTF-8. Both are detected instead of
+ * configured: encoding by BOM/UTF-8 validity, delimiter by counting
+ * candidates in the header line. Multiline quoted values (e.g. RTE
+ * descriptions) are handled by fgetcsv on a temp stream.
+ */
+final class CsvReader
+{
+    /**
+     * @return array{columns: array<int,string>, rows: array<int,array<string,string>>}
+     */
+    public function parse(string $content): array
+    {
+        if (str_starts_with($content, "\xEF\xBB\xBF")) {
+            $content = substr($content, 3);
+        }
+        if (!mb_check_encoding($content, 'UTF-8')) {
+            $content = mb_convert_encoding($content, 'UTF-8', 'Windows-1252');
+        }
+
+        $firstLine = strtok($content, "\r\n") ?: '';
+        $delimiter = ';';
+        $best = 0;
+        foreach ([';', ',', "\t"] as $candidate) {
+            $count = substr_count($firstLine, $candidate);
+            if ($count > $best) {
+                $best = $count;
+                $delimiter = $candidate;
+            }
+        }
+
+        $stream = fopen('php://temp', 'r+');
+        fwrite($stream, $content);
+        rewind($stream);
+
+        $header = fgetcsv($stream, null, $delimiter, '"', '');
+        if (!is_array($header)) {
+            fclose($stream);
+            return ['columns' => [], 'rows' => []];
+        }
+        $columns = [];
+        foreach ($header as $i => $name) {
+            $name = trim((string)$name);
+            $columns[$i] = $name !== '' ? $name : ('column_' . ($i + 1));
+        }
+
+        $rows = [];
+        while (($data = fgetcsv($stream, null, $delimiter, '"', '')) !== false) {
+            if ($data === [null] || $data === ['']) {
+                continue; // blank line
+            }
+            $row = [];
+            $hasContent = false;
+            foreach ($columns as $i => $name) {
+                $value = trim((string)($data[$i] ?? ''));
+                $row[$name] = $value;
+                if ($value !== '') {
+                    $hasContent = true;
+                }
+            }
+            if ($hasContent) {
+                $rows[] = $row;
+            }
+        }
+        fclose($stream);
+
+        return ['columns' => array_values($columns), 'rows' => $rows];
+    }
+}