ver. 0.278: Settings + Languages frontend migration, bug fix get_single_settings_value

- Add cached frontend methods to existing Domain repositories (allSettings, getSingleValue, defaultLanguage, activeLanguages, translations)
- Convert front\factory\Settings and Languages to facades delegating to Domain repositories
- Fix get_single_settings_value() - was hardcoded to 'firm_name', now uses $param correctly
- Add CacheHandler stub methods (get/set/exists) to test bootstrap
- Establish architectural rule: Domain classes are shared between admin and frontend

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

updates/changelog.php

@@ -1,3 +1,7 @@
+<b>ver. 0.278 - 16.02.2026</b><br />
+- UPDATE - migracja Settings + Languages do wspolnych klas Domain (z cache Redis)
+- FIX - `get_single_settings_value()` — parametr `$param` poprawnie uzywany (wczesniej hardcoded `firm_name`)
+<hr>
 <b>ver. 0.277 - 16.02.2026</b><br />
 - NEW - migracja modulu `ShopProduct` (factory) — pelna migracja ~40 metod do `ProductRepository` + ~30 akcji w `ShopProductController`
 - NEW - migracja modulu `Dashboard` do Domain + DI (`DashboardRepository`, `DashboardController`)

updates/versions.php

@@ -1,5 +1,5 @@
 <?
-$current_ver = 276;
+$current_ver = 278;
 
 for ($i = 1; $i <= $current_ver; $i++)
 {