Fix QA review findings: server-side validation, notes encoding, dashboard totals

Validate document lines on the server and recompute their totals, store notes with quotes/markup/emoji (utf8mb4, idempotent escaping, decode in form fields), exclude transfers from company-wide stock in/out, count revenue from confirmed orders only, one low-stock rule everywhere, list unapproved lots, natural bin sort, stable order/PO sort, status tiles that add up.

app/assets/utils/classes/QuotationManager.php

@@ -1,5 +1,6 @@
 <?php
 require_once __DIR__ . '/DocumentNumberManager.php';
+require_once __DIR__ . '/DocumentValidator.php';
 require_once __DIR__ . '/../classes_ac/PostingWindowGuard.php';
 
 /**
@@ -173,8 +174,9 @@ class QuotationManager
     public function save(array $data, array $logging): int
     {
         $id       = (int)($data['id'] ?? 0);
-        $items    = $data['items'] ?? [];
-        $discount = (float)($data['discount'] ?? 0);
+        $items    = DocumentValidator::normaliseLines($data['items'] ?? [], 'Quotation');
+        $data['items'] = $items;
+        $discount = DocumentValidator::discount($data['discount'] ?? 0, array_sum(array_column($items, 'total_price')));
 
         $quotation_date = (string)($data['quotation_date'] ?? '');
         $valid_until    = (string)($data['valid_until']    ?? '');