feat: createDockerFolder & setDockerFolderChildren mutations (#1558)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added the ability to create Docker folders and set folder children via
new GraphQL mutations in the Docker organizer.
* Enhanced organizer management with pure functions for folder creation
and child assignment, ensuring immutability.

* **Bug Fixes**
* Improved validation to prevent empty or invalid folder entries in the
organizer structure.

* **Tests**
* Added comprehensive tests for folder creation, child assignment, and
organizer resolution, including edge cases and immutability checks.
* Updated test guidelines to focus on observable behavior and error
handling best practices.

* **Documentation**
  * Expanded testing best practices in project documentation.

* **Chores**
  * Updated ignore rules for local configuration files.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.cursor/rules/web-testing-rules.mdc

@@ -4,6 +4,10 @@ globs: **/*.test.ts,**/__test__/components/**/*.ts,**/__test__/store/**/*.ts,**/
 alwaysApply: false
 ---
 
+## General Testing Best Practices
+- **Error Testing:** Use `.rejects.toThrow()` without arguments to test that functions throw errors. Don't test exact error message strings unless the message format is specifically what you're testing
+- **Focus on Behavior:** Test what the code does, not implementation details like exact error message wording
+
 ## Vue Component Testing Best Practices
 - This is a Nuxt.js app but we are testing with vitest outside of the Nuxt environment
 - Nuxt is currently set to auto import so some vue files may need compute or ref imported