refactor(entities): unifica loader d'animacio via AnimationComponent::fromYaml i elimina fps:

data/entities/dust/dust.yaml

@@ -16,7 +16,7 @@ flags:
 # apropiada via `setVariant` abans del primer tick.
 #   jump: frames 0..6 (7 frames) → reproduït al despegue.
 #   land: frames 7..12 (6 frames) → reproduït a l'aterratge.
-# fps: 10 = 100 ms per frame.
+# frame_ms: 67 ≈ 15 fps (1000 / 67 ≈ 14.9 fps).
 animations:
-  jump: { frames: [0, 1, 2, 3, 4, 5, 6], fps: 15, loop: false }
-  land: { frames: [7, 8, 9, 10, 11, 12], fps: 15, loop: false }
+  jump: { frames: [0, 1, 2, 3, 4, 5, 6], frame_ms: 67, loop: false }
+  land: { frames: [7, 8, 9, 10, 11, 12], frame_ms: 67, loop: false }