Qol/fix spelling mistakes

[Brophy]

Summary

Fix spelling mistakes in comments, documentation, and code identifiers across Client/, Server/ and Shared/

Motivation

Accumulated spelling mistakes in the codebase may make it harder to search the code.

No GitHub issue — purely a quality of life / housekeeping change.

Test plan

• Confirm the project compiles successfully.
• All other changes are in comments or string literals and carry no functional risk.

Checklist

• Your code should follow the coding guidelines.
• Smaller pull requests are easier to review. If your pull request is beefy, your pull request should be reviewable commit-by-commit.