Add cloth simulation page with WGSL shaders

Introduce a new cloth simulation feature: adds ClothComponent (TS/HTML/SCSS) and WGSL compute/vertex/fragment shaders implementing an XPBD-based cloth sim. Wire up routing and RouterConstants, add the cloth entry to the algorithms list, and add English/German i18n strings. Also include small refactors/renames for algorithm-category and algorithms.service imports and update BabylonCanvas to tolerate optional shader configuration and avoid null access during setup.

src/app/constants/RouterConstants.ts

@@ -9,6 +9,7 @@ import {LabyrinthComponent} from '../pages/algorithms/pathfinding/labyrinth/laby
 import {FractalComponent} from '../pages/algorithms/fractal/fractal.component';
 import {Fractal3dComponent} from '../pages/algorithms/fractal3d/fractal3d.component';
 import PendulumComponent from '../pages/algorithms/pendulum/pendulum.component';
+import {ClothComponent} from '../pages/algorithms/cloth/cloth.component';
 
 export class RouterConstants {
 
@@ -72,6 +73,12 @@ export class RouterConstants {
     COMPONENT: PendulumComponent
   };
 
+  static readonly CLOTH = {
+    PATH: 'algorithms/cloth',
+    LINK: '/algorithms/cloth',
+    COMPONENT: ClothComponent
+  };
+
   static readonly IMPRINT = {
     PATH: 'imprint',
     LINK: '/imprint',