fix: ukloni DOCX zaštitu za uređivanje izvještaja

Generirani servisni DOCX preuzimao je document/write zaštitu iz predloška pa je Word datoteka bila neurediva.\n\nDodano je uklanjanje documentProtection/writeProtection/readOnlyRecommended postavki pri kreiranju DOCX dokumenta te regresijski test koji provjerava da zaštita nije prisutna u word/settings.xml.\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/modules/fleet/views.py

@@ -1607,11 +1607,32 @@ def _create_docx_document(template_name=None):
     except ModuleNotFoundError:
         raise DRFValidationError({"detail": "DOCX generiranje nije dostupno: nedostaje python-docx paket."})
     if not template_name:
-        return Document()
+        document = Document()
+        _remove_docx_edit_restrictions(document)
+        return document
     template_path = DOCX_TEMPLATE_DIR / template_name
     if not template_path.exists():
         raise DRFValidationError({"detail": f"DOCX template nije pronađen: {template_name}."})
-    return Document(str(template_path))
+    document = Document(str(template_path))
+    _remove_docx_edit_restrictions(document)
+    return document
+
+
+def _remove_docx_edit_restrictions(document):
+    try:
+        settings_element = document.settings.element
+    except AttributeError:
+        return document
+
+    protected_tags = (
+        '{http://schemas.openxmlformats.org/wordprocessingml/2006/main}documentProtection',
+        '{http://schemas.openxmlformats.org/wordprocessingml/2006/main}writeProtection',
+        '{http://schemas.openxmlformats.org/wordprocessingml/2006/main}readOnlyRecommended',
+    )
+    for tag_name in protected_tags:
+        for element in list(settings_element.findall(tag_name)):
+            settings_element.remove(element)
+    return document
 
 
 def _set_docx_cell_text(table, row_index, col_index, value):