fix: editors can create records in the folders outside the sites again

Editors got "recordEditAccessInternals() check failed [ERROR: The
"languageField" field named "sys_language_uid" was not found in testing
record!]" for every new record of our tables, e.g. a hotel's additional
code or a new hotel. The record folders lie on the root level, outside
every site, and no form submitted the language field. TYPO3 10 then took
language 0 from sys_language; since TYPO3 11, DataHandler only takes the
default language from the record's site and sets none without a site, so
the access check for non-admins fails.

As stock TYPO3 expects it, the forms now submit the language: a Language
tab with sys_language_uid (default 0) and l10n_parent in the 27
language-aware tables of ep_products and ep_theme. Matchcodes (a hotel's
additional codes) are no longer translatable at all: none was ever
translated, and the feed, the API and the import read them without
language handling.

LabelService no longer reads from a missing record when the form of a
new record asks for a label.

Checked locally as an editor: FormEngine preselects language 0, and new
hotels, products, FAQs and additional codes are saved.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/ep_theme/Configuration/TCA/tx_eptheme_domain_model_lineup.php

@@ -28,7 +28,7 @@ return [
 	],
 	'types' => [
 		'1' => [
-			'showitem' => 'hidden, name, description, image, --palette--;;social',
+			'showitem' => 'hidden, name, description, image, --palette--;;social, --div--;LLL:EXT:core/Resources/Private/Language/Form/locallang_tabs.xlf:language, sys_language_uid, l10n_parent',
 		],
 	],
 	'palettes' => [
@@ -39,7 +39,7 @@ return [
 		'sys_language_uid' => [
 			'exclude' => 0,
 			'label' => 'LLL:EXT:core/Resources/Private/Language/locallang_general.xlf:LGL.language',
-			'config' => ['type' => 'language'],
+			'config' => ['type' => 'language', 'default' => 0],
 		],
 		'l10n_parent' => [
 			'displayCond' => 'FIELD:sys_language_uid:>:0',

packages/ep_theme/Configuration/TCA/tx_eptheme_domain_model_slide.php

@@ -28,7 +28,7 @@ return [
 	],
 	'types' => [
 		'1' => [
-			'showitem' => '--palette--;;top, --palette--;;headlines, --palette--;;linkbutton, image',
+			'showitem' => '--palette--;;top, --palette--;;headlines, --palette--;;linkbutton, image, --div--;LLL:EXT:core/Resources/Private/Language/Form/locallang_tabs.xlf:language, sys_language_uid, l10n_parent',
 		],
 	],
 	'palettes' => [
@@ -41,7 +41,7 @@ return [
 		'sys_language_uid' => [
 			'exclude' => 0,
 			'label' => 'LLL:EXT:core/Resources/Private/Language/locallang_general.xlf:LGL.language',
-			'config' => ['type' => 'language'],
+			'config' => ['type' => 'language', 'default' => 0],
 		],
 		'l10n_parent' => [
 			'displayCond' => 'FIELD:sys_language_uid:>:0',