test(continuum): Update test suite includes for new architecture

Removed old test files:
- test_kernel_allocations.jl (deleted)

Added new test files:
- test_dofs_per_node.jl - DOF mapping tests
- test_dof_mapping.jl - Field to DOF mapping
- test_helpers.jl - Utility function tests
- test_kernel_functions.jl - Kernel computation tests
- test_reset_functions.jl - Cache reset tests
- test_cache_updates.jl - Three-phase cache update tests
- test_compute_block.jl - Block computation tests
- test_full_assembly.jl - End-to-end assembly tests
- test_validation_hex8.jl - Hex8 element validation

Test suite restructured to match new cache architecture.

test/domains/continuum/runtests.jl

@@ -1,80 +1,76 @@
-# This file is a part of JuliaFEM.
-# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
-
 """
 Test suite for continuum mechanics domain.
 
-This test suite ensures:
-1. Zero-allocation property is maintained for performance-critical paths
-2. Type stability for all integration and assembly functions
-3. Material trait system works correctly with generic integration
-4. Backward compatibility with existing code
+Organized by priority:
+1. Fix errors first
+2. Then correctness
+3. Finally zero allocations
 
-Run with: include("test/domains/continuum/runtests.jl")
+Run with: julia --project=. test/domains/continuum/runtests.jl
 """
 
 using Test
 using JuliaFEM
+using Tensors
+using LinearAlgebra
+
+# Load shared helper functions
+include("test_helpers.jl")
 
 @testset "Continuum Domain Tests" begin
 
     @testset "Material Trait System" begin
         @testset "LinearElastic traits" begin
             mat = LinearElastic(E=210e9, ν=0.3)
-
             @test material_behavior(mat) isa StatelessConstantTangent
             @test needs_deformation(mat) == false
             @test needs_state(mat) == false
-
-            println("  ✓ LinearElastic: StatelessConstantTangent")
         end
 
         @testset "NeoHookean traits" begin
             mat = NeoHookean(μ=1e6, λ=1e9)
-
             @test material_behavior(mat) isa StatelessStrainDependent
             @test needs_deformation(mat) == true
             @test needs_state(mat) == false
-
-            println("  ✓ NeoHookean: StatelessStrainDependent")
         end
-
-        # PerfectPlasticity will be tested once it's exported
-        # @testset "PerfectPlasticity traits" begin
-        #     mat = PerfectPlasticity(E=210e9, ν=0.3, σ_y=250e6, H=1e9)
-        #
-        #     @test material_behavior(mat) isa StatefulStrainDependent
-        #     @test needs_deformation(mat) == true
-        #     @test needs_state(mat) == true
-        #
-        #     println("  ✓ PerfectPlasticity: StatefulStrainDependent")
-        # end
     end
 
-    @testset "Zero-Allocation Tests" begin
-        println("\n  Running allocation tests...")
-        include("test_kernel_allocations.jl")
+    @testset "Hex8 Element Validation (Correctness)" begin
+        include("test_validation_hex8.jl")
     end
 
-    # Type stability tests work when run directly but cause issues in test suite
-    # Run manually with: julia --project=. test/domains/continuum/test_type_stability.jl
-    # @testset "Type Stability Tests" begin
-    #     println("\n  Running type stability tests...")
-    #     include("test_type_stability.jl")
-    # end
+    @testset "DOF Mapping (Correctness)" begin
+        include("test_dofs_per_node.jl")
+        include("test_dof_mapping.jl")
+    end
 
-    # Stiffness block allocation tests are more detailed/diagnostic
-    # Uncomment to run detailed allocation profiling:
-    # @testset "Stiffness Block Allocation Tests" begin
-    #     println("\n  Running detailed stiffness block allocation tests...")
-    #     include("test_stiffness_block_allocations.jl")
-    # end
+    @testset "Cache Reset Functions" begin
+        include("test_reset_functions.jl")
+    end
+
+    @testset "Cache Update Functions (Three-Phase API)" begin
+        include("test_cache_updates.jl")
+    end
+
+    @testset "Kernel Functions" begin
+        include("test_kernel_functions.jl")
+        include("test_compute_block.jl")
+    end
+
+    @testset "Full Assembly Workflow" begin
+        include("test_full_assembly.jl")
+    end
 end
 
 println("\n" * "="^70)
 println("CONTINUUM DOMAIN TEST SUMMARY")
 println("="^70)
-println("✓ Material trait system verified")
-println("✓ Zero-allocation property maintained")
-println("✓ Type stability confirmed")
+println("Test organization:")
+println("  1. Material traits - Type system verification")
+println("  2. Hex8 validation - Correctness against analytical solution")
+println("  3. DOF mapping - Index computation correctness")
+println("  4. Cache resets - Zero-allocation reset functions")
+println("  5. Cache updates - Three-phase update workflow")
+println("  6. Kernel functions - Weak form and integration")
+println("  7. Full assembly - Complete workflow validation")
 println("="^70)