test(quadrature): add pyramid quadrature test

Test file included in test/quadrature/runtests.jl
Tests quadrature rules for pyramid elements

test/quadrature/test_pyramids.jl

@@ -0,0 +1,39 @@
+# This file is a part of JuliaFEM.
+# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
+
+@testset "Pyramid Quadrature Rules" begin
+
+    @testset "GaussLegendre{2} - 5 points (default)" begin
+        points = get_quadrature_points(Pyramid, GaussLegendre{2}())
+        @test length(points) == 5
+
+        # Check weights sum to volume of reference pyramid
+        # Reference pyramid with base [-1,1]² and height from z=0 to z=1
+        # Volume = (1/3) * base_area * height = (1/3) * 4 * 1 = 4/3
+        weight_sum = sum(p.weight for p in points)
+        @test weight_sum ≈ 4/3 rtol=1e-10
+
+        # Check that there are 4 base points and 1 elevated point
+        # (This is topology of typical pyramid quadrature)
+        z_coords = [p.coords[3] for p in points]
+        @test length(unique(z_coords)) >= 2  # At least 2 different z-levels
+    end
+
+    @testset "GaussLegendre{2,:B} - 5 points (variant B)" begin
+        points = get_quadrature_points(Pyramid, GaussLegendre{2,:B}())
+        @test length(points) == 5
+
+        # Check weights sum to 4/3
+        weight_sum = sum(p.weight for p in points)
+        @test weight_sum ≈ 4/3 rtol=1e-10
+
+        # All weights equal for variant B
+        @test all(p.weight ≈ 2/15 for p in points)
+    end
+
+    @testset "Point coordinates are Vec type" begin
+        points = get_quadrature_points(Pyramid, GaussLegendre{2}())
+        @test points[1].coords isa Vec{3,Float64}
+        @test !(points[1].coords isa SVector)
+    end
+end