De-emphasize production language, resolve TODOs, and clean up files

- Renamed 02_engineering_context_for_production.ipynb to 02_crafting_and_optimizing_context.ipynb
- De-emphasized 'production' language throughout README.md and COURSE_SUMMARY.md
- Changed 'production-ready' to 'practical' and 'reusable' patterns
- Changed 'deploy to production' to 'apply to real-world use cases'
- Resolved 3 TODO items in COURSE_SUMMARY.md
- Removed backup and executed notebook files from section 3
- Updated all references to renamed notebook
- Executed Section 2 notebooks with outputs

Author: nkanu17

python-recipes/context-engineering/COURSE_SUMMARY.md

@@ -72,7 +72,7 @@ By the end of this section, you will be able to:
 
 ---
 
-### 02_engineering_context_for_production.ipynb
+### 02_crafting_and_optimizing_context.ipynb
 
 **Time:** 90-105 minutes