justfile: standardise test recipes to lint-php/lint-css/lint-js/test + add fix recipe

- Removed ambiguous aliases: phpstan, cs-check, syntax
- Split lint-biome into lint-css and lint-js with correct paths
- Added lint meta-recipe and fix recipe (biome --unsafe + php-cs-fixer)
- Fixed FormBootstrap dead null check, CSS shorthand override bug
- Updated phpstan baseline, suppressed noDescendingSpecificity/noInnerDeclarations
- Applied ~74 biome auto-fixes across CSS/JS

app/src/Form/FormBootstrap.php

@@ -47,9 +47,6 @@ class FormBootstrap
             if (is_array($formData[$key])) {
                 return $formData[$key];
             }
-            if ($formData[$key] === null) {
-                return $default;
-            }
             return htmlspecialchars((string)$formData[$key]);
         };
     }