Bootstrap Unit Tests [AARD-1942] - #1226

Task

AARD-1942

Write unit tests for app startup and bootstrapping

Symptom

Validate that the whole loading/rendering pipeline from main.tsx down to all the components works as expected

Solution

While the original two pull requests (#1175 and #1179) were more verbose, I think that this version covers the use cases we care about. The idea is to capture the important parts of boostrapping without being obnoxious when anything normal changes

• Google Analytics script loading
• That mounts
• That there are no expected DOM elements that are missing (try changing the IDs of the expected joystick elements in InputSystem.ts#L201)
• That the worldInit function is called (i.e. we get to the start of World.test.ts)
• External CSS loading (TODO)

Verification

Go around messing with things that you think should be in scope (causing errors on startup, messing with main.tsx, breaking the main menu screen, etc, and see if the tests are passing.

Before merging, ensure the following criteria are met:

• All acceptance criteria outlined in the ticket are met.
• Necessary test cases have been added and updated.
• A feature toggle or safe disable path has been added (if applicable).
• User-facing polish:
  • Ask: "Is this ready-looking?"
• Cross-linking between Jira and GitHub:
  • PR links to the relevant Jira issue.
  • Jira ticket has a comment referencing this PR.