Simplify renovate commands and add demo instructions

- Remove regular renovate command, keep only renovate:jest
- Update renovate:jest to use static renovate.json configuration
- Update renovate.json to target Jest dependencies specifically
- Add demos/fixing-renovate-dependencies.md with sales engineer instructions
- Remove code comments from unit test files
- Clean up debug files and update .gitignore

Author: loujaybee

.gitignore

@@ -41,3 +41,4 @@ services/database/database.sqlite
 # Renovate debug files
 renovate_debug.txt
 renovate_output.txt
+jest_debug.txt