Simplify module test execution for notebook compatibility

Removed redundant test calls from all modules:
- Eliminated verbose if __name__ == '__main__': blocks
- Removed duplicate individual test calls
- Each module now simply calls test_module() directly

Changes made to all 9 modules:
- Module 01 (Tensor): Simplified from 16-line main block to 1 line
- Module 02 (Activations): Simplified from 13-line main block to 1 line
- Module 03 (Layers): Simplified from 17-line main block to 1 line
- Module 04 (Losses): Simplified from 20-line main block to 1 line
- Module 05 (Autograd): Simplified from 19-line main block to 1 line
- Module 06 (Optimizers): Simplified from 17-line main block to 1 line
- Module 07 (Training): Simplified from 16-line main block to 1 line
- Module 08 (DataLoader): Simplified from 17-line main block to 1 line
- Module 09 (Spatial): Simplified from 14-line main block to 1 line

Impact:
- Notebook-friendly: Tests run immediately in Jupyter environments
- No redundancy: test_module() already runs all unit tests
- Cleaner code: ~140 lines of redundant code removed
- Better for students: Simpler, more direct execution flow

modules/06_optimizers/optimizers_dev.py

@@ -1408,26 +1408,8 @@ def test_module():
     print("Run: tito module complete 06_optimizers")
 
 # %%
-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!")
+# Run comprehensive module test
+test_module()
 
 # %% [markdown]
 """