✨ Add structural organization headers to 10_optimizers module

- Added ## 🔧 DEVELOPMENT section before Step 1 where development begins
- Added ## 🤖 AUTO TESTING section before nbgrader block
- Updated to ## 🎯 MODULE SUMMARY: Optimization Algorithms

Improves notebook organization without changing any code logic or content.

modules/source/10_optimizers/optimizers_dev.py

@@ -151,6 +151,11 @@ But **naive gradient descent** has problems:
 4. **Integration**: Complete training loop with optimizers
 """
 
+# %% [markdown]
+"""
+## 🔧 DEVELOPMENT
+"""
+
 # %% [markdown]
 """
 ## Step 1: Understanding Gradient Descent
@@ -1424,6 +1429,11 @@ Time to test your implementation! This section uses TinyTorch's standardized tes
 **This testing section is locked** - it provides consistent feedback across all modules and cannot be modified.
 """
 
+# %% [markdown]
+"""
+## 🤖 AUTO TESTING
+"""
+
 # %% nbgrader={"grade": false, "grade_id": "standardized-testing", "locked": true, "schema_version": 3, "solution": false, "task": false}
 # =============================================================================
 # STANDARDIZED MODULE TESTING - DO NOT MODIFY
@@ -1446,7 +1456,7 @@ if __name__ == "__main__":
 
 # %% [markdown]
 """
-## 🎯 Module Summary: Optimization Mastery!
+## 🎯 MODULE SUMMARY: Optimization Algorithms
 
 Congratulations! You've successfully implemented the optimization algorithms that power all modern neural network training: