feature: hud (#37)

* build: replace FetchContent with direct includes for glm

* build(deps): replace SOIL2 with stb for image and vorbis decoding

* build: replace FetchContent with direct includes for toml++

* refactor(texture): bump block texture size to 512 and disable items tab

* feat: add hotbar system with ItemStack and RowLayout

* fix(ui): restrict Ctrl key handling to typing mode

* feat(ui): add widget border support and highlight selected hotbar slot

* fix(ui): update borders on scale change and correct Image width

- Added update_border() calls in set_scale() for Button, ChatBox, Image, Label, and TextField.
- Fixed Image::width() to multiply by width instead of height.
- Added early return in Widget::update_border() if border is not supported.

* feat(ui): add border visual feedback on slider drag

* feat(ui): add ItemSlot widget and refactor hotbar to use it

* feat(world_scene): add inventory UI and pause type enum

* feat(ui): add item slot tooltip and make window size static

* fix(ui label): account for background offset in width/height

* refactor(ui): centralize item info label in inventory and add update

* feat(ui): add hotbar interaction in inventory UI

* fix(inventory-ui): correct row creation logic for first item

The loop starting at index 0 created a new row on the first iteration
(i % 10 == 0). Shift the loop to start at 1 and adjust modulus condition
to create rows correctly every 10 items.

* feat(block): add name_key for localized block names

Add `name_key` field to all block TOML definitions, enabling per-block localization. Update `BlockData` struct and `BlockManager` with `local_name()` method that returns a localized string via the translation system. Add corresponding entries to `en_US.json` and `zh_CN.json`. Modify inventory UI to use the localized name when displaying block info, and fix a bug where emptying a hotbar slot did not clear the item locally.

* fix(ui): change inventory item slot color from white to gray

* fix(ui): add missing include for std::array

src/tools/shader_tools.cpp

@@ -5,6 +5,7 @@
 
 #include <filesystem>
 #include <fstream>
+#include <stb_image.h>
 #include <unordered_set>
 
 namespace Cubed {
@@ -171,7 +172,7 @@ void delete_image_data(unsigned char* data) {
     if (data == nullptr) {
         return;
     }
-    SOIL_free_image_data(data);
+    stbi_image_free(data);
 }
 
 ImageData load_image_data(const std::string& tex_image_path, bool check_exist) {
@@ -181,9 +182,8 @@ ImageData load_image_data(const std::string& tex_image_path, bool check_exist) {
     }
     unsigned char* data = nullptr;
     int width, height, channels;
-    data =
-        SOIL_load_image(path.string().c_str(), &width, &height, &channels,
-                        SOIL_LOAD_RGBA); // Materials are all RGBA; must force
+    data = stbi_load(path.string().c_str(), &width, &height, &channels,
+                     STBI_rgb_alpha); // Materials are all RGBA; must force
     // RGBA, otherwise sampling will fail.
     if (check_exist) {
         if (!data) {