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/glm/gtx/matrix_factorisation.inl

@@ -0,0 +1,84 @@
+/// @ref gtx_matrix_factorisation
+
+namespace glm
+{
+	template <length_t C, length_t R, typename T, qualifier Q>
+	GLM_FUNC_QUALIFIER mat<C, R, T, Q> flipud(mat<C, R, T, Q> const& in)
+	{
+		mat<R, C, T, Q> tin = transpose(in);
+		tin = fliplr(tin);
+		mat<C, R, T, Q> out = transpose(tin);
+
+		return out;
+	}
+
+	template <length_t C, length_t R, typename T, qualifier Q>
+	GLM_FUNC_QUALIFIER mat<C, R, T, Q> fliplr(mat<C, R, T, Q> const& in)
+	{
+		mat<C, R, T, Q> out;
+		for (length_t i = 0; i < C; i++)
+		{
+			out[i] = in[(C - i) - 1];
+		}
+
+		return out;
+	}
+
+	template <length_t C, length_t R, typename T, qualifier Q>
+	GLM_FUNC_QUALIFIER void qr_decompose(mat<C, R, T, Q> const& in, mat<(C < R ? C : R), R, T, Q>& q, mat<C, (C < R ? C : R), T, Q>& r)
+	{
+		// Uses modified Gram-Schmidt method
+		// Source: https://en.wikipedia.org/wiki/Gram%E2%80%93Schmidt_process
+		// And https://en.wikipedia.org/wiki/QR_decomposition
+
+		//For all the linearly independs columns of the input...
+		// (there can be no more linearly independents columns than there are rows.)
+		for (length_t i = 0; i < (C < R ? C : R); i++)
+		{
+			//Copy in Q the input's i-th column.
+			q[i] = in[i];
+
+			//j = [0,i[
+			// Make that column orthogonal to all the previous ones by substracting to it the non-orthogonal projection of all the previous columns.
+			// Also: Fill the zero elements of R
+			for (length_t j = 0; j < i; j++)
+			{
+				q[i] -= dot(q[i], q[j])*q[j];
+				r[j][i] = 0;
+			}
+
+			//Now, Q i-th column is orthogonal to all the previous columns. Normalize it.
+			q[i] = normalize(q[i]);
+
+			//j = [i,C[
+			//Finally, compute the corresponding coefficients of R by computing the projection of the resulting column on the other columns of the input.
+			for (length_t j = i; j < C; j++)
+			{
+				r[j][i] = dot(in[j], q[i]);
+			}
+		}
+	}
+
+	template <length_t C, length_t R, typename T, qualifier Q>
+	GLM_FUNC_QUALIFIER void rq_decompose(mat<C, R, T, Q> const& in, mat<(C < R ? C : R), R, T, Q>& r, mat<C, (C < R ? C : R), T, Q>& q)
+	{
+		// From https://en.wikipedia.org/wiki/QR_decomposition:
+		// The RQ decomposition transforms a matrix A into the product of an upper triangular matrix R (also known as right-triangular) and an orthogonal matrix Q. The only difference from QR decomposition is the order of these matrices.
+		// QR decomposition is Gram-Schmidt orthogonalization of columns of A, started from the first column.
+		// RQ decomposition is Gram-Schmidt orthogonalization of rows of A, started from the last row.
+
+		mat<R, C, T, Q> tin = transpose(in);
+		tin = fliplr(tin);
+
+		mat<R, (C < R ? C : R), T, Q> tr;
+		mat<(C < R ? C : R), C, T, Q> tq;
+		qr_decompose(tin, tq, tr);
+
+		tr = fliplr(tr);
+		r = transpose(tr);
+		r = fliplr(r);
+
+		tq = fliplr(tq);
+		q = transpose(tq);
+	}
+} //namespace glm