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

include/toml++/impl/unicode.inl

@@ -0,0 +1,60 @@
+//# This file is a part of toml++ and is subject to the the terms of the MIT license.
+//# Copyright (c) Mark Gillard <mark.gillard@outlook.com.au>
+//# See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text.
+// SPDX-License-Identifier: MIT
+#pragma once
+
+//# {{
+#include "preprocessor.hpp"
+#if !TOML_IMPLEMENTATION
+#error This is an implementation-only header.
+#endif
+//# }}
+
+#include "unicode.hpp"
+#include "simd.hpp"
+#include "header_start.hpp"
+
+TOML_IMPL_NAMESPACE_START
+{
+	TOML_PURE_GETTER
+	TOML_EXTERNAL_LINKAGE
+	bool is_ascii(const char* str, size_t len) noexcept
+	{
+		const char* const end = str + len;
+
+#if TOML_HAS_SSE2 && (128 % CHAR_BIT) == 0
+		{
+			constexpr size_t chars_per_vector = 128u / CHAR_BIT;
+
+			if (const size_t simdable = len - (len % chars_per_vector))
+			{
+				__m128i mask = _mm_setzero_si128();
+				for (const char* const e = str + simdable; str < e; str += chars_per_vector)
+				{
+					const __m128i current_bytes = _mm_loadu_si128(reinterpret_cast<const __m128i*>(str));
+					mask						= _mm_or_si128(mask, current_bytes);
+				}
+				const __m128i has_error = _mm_cmpgt_epi8(_mm_setzero_si128(), mask);
+
+#if TOML_HAS_SSE4_1
+				if (!_mm_testz_si128(has_error, has_error))
+					return false;
+#else
+				if (_mm_movemask_epi8(_mm_cmpeq_epi8(has_error, _mm_setzero_si128())) != 0xFFFF)
+					return false;
+#endif
+			}
+		}
+#endif
+
+		for (; str < end; str++)
+			if (static_cast<unsigned char>(*str) > 127u)
+				return false;
+
+		return true;
+	}
+}
+TOML_IMPL_NAMESPACE_END;
+
+#include "header_end.hpp"