refactor: use english for routes, parameters and internal messages

src/Entity/ResourceType.php

@@ -8,13 +8,14 @@ namespace App\Entity;
  * The kinds of thing that can be booked.
  *
  * **This enum is the extension point.** The dashboard builds one tile per case, the board route
- * accepts one slug per case, and the floor plan is looked up by convention from the case's
- * value. Adding a third bookable kind is therefore: a case here, a
+ * accepts one backing value per case, and the floor plan is looked up by convention from that
+ * same value. Adding a third bookable kind is therefore: a case here, a
  * `templates/board/plan/_<value>.html.twig` with its geometry, and rows in `app:seed`. Nothing
  * else needs editing — in particular no template lists the kinds by hand.
  *
- * The backing values are persisted in `resource.type`, which is why they stay English while the
- * URLs do not: `slug()` is what appears in a path, so the routes read German like the rest.
+ * The backing value is both what is persisted in `resource.type` and what appears in a URL, so
+ * there is no slug mapping to keep in sync. The label, plural and description are the only
+ * things here anyone sees, which is why they are the only German ones.
  */
 enum ResourceType: string
 {
@@ -52,24 +53,4 @@ enum ResourceType: string
             self::PARKING => 'lucide:car',
         };
     }
-
-    /** What appears in a URL. */
-    public function slug(): string
-    {
-        return match ($this) {
-            self::DESK => 'schreibtische',
-            self::PARKING => 'parkplaetze',
-        };
-    }
-
-    public static function fromSlug(string $slug): self
-    {
-        foreach (self::cases() as $case) {
-            if ($case->slug() === $slug) {
-                return $case;
-            }
-        }
-
-        throw new \ValueError(\sprintf('"%s" ist kein bekannter Buchungsbereich.', $slug));
-    }
 }