Fix all remaining modules to prevent test execution on import

Wrapped test code in if __name__ == '__main__': guards for:
- Module 02 (activations): 7 test calls protected
- Module 03 (layers): 7 test calls protected
- Module 04 (losses): 10 test calls protected
- Module 05 (autograd): 7 test calls protected
- Module 06 (optimizers): 8 test calls protected
- Module 07 (training): 7 test calls protected
- Module 09 (spatial): 5 test calls protected

Impact:
- All modules can now be imported cleanly without test execution
- Tests still run when modules are executed directly
- Clean dependency chain throughout the framework
- Follows Python best practices for module structure

This completes the fix for the entire module system. Modules can now
properly import from each other without triggering test code execution.

modules/06_optimizers/optimizers_dev.py

@@ -345,8 +345,6 @@ def test_unit_optimizer_base():
 
     print("✅ Base Optimizer works correctly!")
 
-test_unit_optimizer_base()
-
 # %% [markdown]
 """
 ## SGD - Stochastic Gradient Descent
@@ -562,8 +560,6 @@ def test_unit_sgd_optimizer():
 
     print("✅ SGD optimizer works correctly!")
 
-test_unit_sgd_optimizer()
-
 # %% [markdown]
 """
 ## Adam - Adaptive Moment Estimation
@@ -807,8 +803,6 @@ def test_unit_adam_optimizer():
 
     print("✅ Adam optimizer works correctly!")
 
-test_unit_adam_optimizer()
-
 # %% [markdown]
 """
 ## AdamW - Adam with Decoupled Weight Decay
@@ -1045,8 +1039,6 @@ def test_unit_adamw_optimizer():
 
     print("✅ AdamW optimizer works correctly!")
 
-test_unit_adamw_optimizer()
-
 # %% [markdown]
 """
 ## 4. Integration: Bringing It Together
@@ -1129,8 +1121,6 @@ def demonstrate_optimizer_integration():
     print("- Adam: Smaller, adaptive steps")
     print("- AdamW: Similar to Adam but with weight decay effects")
 
-demonstrate_optimizer_integration()
-
 # %% [markdown]
 """
 ## 5. Systems Analysis: Optimizer Performance and Memory
@@ -1214,8 +1204,6 @@ def analyze_optimizer_memory_usage():
     print("- Memory scales linearly with model size")
     print("- Trade-off: More memory for better convergence")
 
-analyze_optimizer_memory_usage()
-
 # %% nbgrader={"grade": false, "grade_id": "optimizer-convergence", "solution": true}
 def analyze_optimizer_convergence_behavior():
     """📊 Analyze convergence behavior of different optimizers."""
@@ -1282,8 +1270,6 @@ def analyze_optimizer_convergence_behavior():
     print("- Adam: Adaptive rates help with different parameter scales")
     print("- AdamW: Similar to Adam with regularization effects")
 
-analyze_optimizer_convergence_behavior()
-
 # %% [markdown]
 """
 ## 🧪 Module Integration Test
@@ -1421,12 +1407,26 @@ def test_module():
     print("🎉 ALL TESTS PASSED! Module ready for export.")
     print("Run: tito module complete 06_optimizers")
 
-test_module()
-
 # %%
 if __name__ == "__main__":
     print("🚀 Running Optimizers module...")
+
+    # Run all unit tests
+    test_unit_optimizer_base()
+    test_unit_sgd_optimizer()
+    test_unit_adam_optimizer()
+    test_unit_adamw_optimizer()
+
+    # Run integration demonstrations
+    demonstrate_optimizer_integration()
+
+    # Run analysis functions
+    analyze_optimizer_memory_usage()
+    analyze_optimizer_convergence_behavior()
+
+    # Run final module test
     test_module()
+
     print("✅ Module validation complete!")
 
 # %% [markdown]