December 2024 and Winter Wonderland 2025 build (#15358)

* feat(content): Winter 2025 build by @CuriousMagpie

* fix(content): add more WW

* fix(content): add more WW

* chore(subproj): update habitica-images

* fix(gala): December 2024 is Winter 2025

* fix(content): lint, background typo, 0 index month

* fix(content): add missing mystery set name

* fix(content): roll back erroneous month indexing

* fix(tests): no 13th month, consider releases in schedule test

* update gear strings

* fix(seasonal): show quest modal

* fix(seasonal): use category-item component

* chore(subproj): update habitica-images

---------

Co-authored-by: CuriousMagpie <eilatan@gmail.com>

website/common/script/content/appearance/backgrounds.js

@@ -638,6 +638,9 @@ const backgrounds = {
   backgrounds112024: {
     castle_hall_with_hearth: { },
   },
+  backgrounds122024: {
+    first_snow_forest: { },
+  },
   eventBackgrounds: {
     birthday_bash: {
       price: 0,