fix: add missing gradle-wrapper.jar files and update gitignore pattern

- Fix gitignore pattern to properly exclude gradle-wrapper.jar files
  using **/gradle/wrapper/gradle-wrapper.jar instead of gradle/wrapper/gradle-wrapper.jar
- Add missing gradle-wrapper.jar for tools example to enable running tests
- Add gradle-wrapper.jar files for all examples and library modules

This allows all example projects to run their tests independently
without requiring parent gradle installation.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: contextablemark

kotlin-sdk/.gitignore

@@ -93,7 +93,7 @@ temp/
 
 # Package files
 *.jar
-!gradle/wrapper/gradle-wrapper.jar
+!**/gradle/wrapper/gradle-wrapper.jar
 *.war
 *.ear
 *.zip