Refactor tests: extract shared utilities and fixtures

.claude/rules.md

@@ -19,7 +19,7 @@ If terminal execution is unavailable or blocked by approvals, ask for approval o
 
 The project has a gold-standard validation suite that rigorously verifies the Navier-Stokes solver:
 
-#### Core Tests (tests/test_physics_validation.cpp) - ~2 min on GPU:
+#### Core Tests (tests/test_physics_validation_advanced.cpp) - ~2 min on GPU:
 
 1. Poiseuille Flow (Analytical)
    - Tests: Viscous terms, pressure gradient, parabolic profile
@@ -50,7 +50,7 @@ The project has a gold-standard validation suite that rigorously verifies the Na
    - Tests: No NaN/Inf, realizability (ν_t >= 0)
    - Validates: Numerical stability
 
-#### Advanced Validation (tests/test_tg_validation.cpp) - ~30 sec:
+#### Taylor-Green Validation (in tests/test_physics_validation_advanced.cpp):
 
 Taylor-Green Vortex Test
 - Initial: u=sin(x)cos(y), v=-cos(x)sin(y) (divergence-free)

.cursorrules

@@ -6,7 +6,7 @@
 
 The project has a **gold-standard validation suite** that rigorously verifies the Navier-Stokes solver:
 
-#### Core Tests (`tests/test_physics_validation.cpp`) - ~2 min on GPU:
+#### Core Tests (`tests/test_physics_validation_advanced.cpp`) - ~2 min on GPU:
 
 1. **Poiseuille Flow (Analytical)**
    - Tests: Viscous terms, pressure gradient, parabolic profile
@@ -37,7 +37,7 @@ The project has a **gold-standard validation suite** that rigorously verifies th
    - Tests: No NaN/Inf, realizability (ν_t ≥ 0)
    - Validates: Numerical stability
 
-#### Advanced Validation (`tests/test_tg_validation.cpp`) - ~30 sec:
+#### Taylor-Green Validation (in `tests/test_physics_validation_advanced.cpp`):
 
 **Taylor-Green Vortex Test**
 - Initial: u=sin(x)cos(y), v=-cos(x)sin(y) (divergence-free)

.github/scripts/compare_cpu_gpu_builds.sh

@@ -33,22 +33,8 @@ mkdir -p cpu_gpu_comparison
     echo "[FAIL] Bitwise CPU reference generation failed!"
     exit 1
 }
-./test_poisson_cpu_gpu_3d --dump-prefix cpu_gpu_comparison/poisson3d || {
-    echo "[FAIL] Poisson 3D CPU reference generation failed!"
-    exit 1
-}
-./test_cpu_gpu_consistency --dump-prefix cpu_gpu_comparison/consistency || {
-    echo "[FAIL] Consistency CPU reference generation failed!"
-    exit 1
-}
-./test_solver_cpu_gpu --dump-prefix cpu_gpu_comparison/solver || {
-    echo "[FAIL] Solver CPU reference generation failed!"
-    exit 1
-}
-./test_time_history_consistency --dump-prefix cpu_gpu_comparison/timehistory || {
-    echo "[FAIL] Time-history CPU reference generation failed!"
-    exit 1
-}
+# Note: test_cpu_gpu_consistency, test_solver_cpu_gpu, test_time_history_consistency
+# were consolidated into test_cpu_gpu_unified (runs within single-build, not cross-build)
 
 echo ""
 echo "--- Step 2: Run GPU and compare against CPU reference ---"
@@ -74,22 +60,7 @@ fi
     echo "[FAIL] Bitwise GPU vs CPU comparison failed!"
     exit 1
 }
-./test_poisson_cpu_gpu_3d --compare-prefix "$WORKDIR/build_ci_cpu_ref/cpu_gpu_comparison/poisson3d" || {
-    echo "[FAIL] Poisson 3D GPU vs CPU comparison failed!"
-    exit 1
-}
-./test_cpu_gpu_consistency --compare-prefix "$WORKDIR/build_ci_cpu_ref/cpu_gpu_comparison/consistency" || {
-    echo "[FAIL] Consistency GPU vs CPU comparison failed!"
-    exit 1
-}
-./test_solver_cpu_gpu --compare-prefix "$WORKDIR/build_ci_cpu_ref/cpu_gpu_comparison/solver" || {
-    echo "[FAIL] Solver GPU vs CPU comparison failed!"
-    exit 1
-}
-./test_time_history_consistency --compare-prefix "$WORKDIR/build_ci_cpu_ref/cpu_gpu_comparison/timehistory" || {
-    echo "[FAIL] Time-history GPU vs CPU comparison failed!"
-    exit 1
-}
+# Note: Additional consistency tests consolidated into test_cpu_gpu_unified (single-build)
 
 echo ""
 echo "[PASS] CPU-only vs GPU-offload comparison completed successfully"

.github/scripts/cpu_sanity_suite.sh

@@ -110,9 +110,8 @@ run_test "3D Gradients" "./test_3d_gradients" 60
 # Poisson solver tests
 echo ""
 echo "--- Poisson Solver Tests ---"
-run_test "Poisson Selection" "./test_poisson_selection" 60
+run_test "Poisson Unified" "./test_poisson_unified" 180
 run_test "Residual Consistency" "./test_residual_consistency" 120
-run_test "Poisson Nullspace" "./test_poisson_nullspace" 120
 
 # MPI guard test
 echo ""

.github/scripts/gpu_correctness_suite.sh

@@ -110,7 +110,7 @@ echo "==================================================================="
 echo "  6. CPU/GPU Consistency Validation (Critical)"
 echo "==================================================================="
 echo ""
-./test_cpu_gpu_consistency
+./test_cpu_gpu_unified
 
 echo ""
 echo "==================================================================="
@@ -125,8 +125,7 @@ echo "==================================================================="
 echo "  8. Physics Validation (Comprehensive)"
 echo "==================================================================="
 echo ""
-./test_physics_validation
-./test_tg_validation
+./test_physics_validation_advanced
 
 echo ""
 echo "==================================================================="