Refresh translations without recreating the window

[DirkDoes]

Purpose of this PR:

Let the localization service own language-change events and have the global facade forward them. XAML translation markup now returns an observable binding that updates on the UI thread.

Refresh persistent layout text and active settings labels/dropdowns in place. Changing the language no longer recreates the main window or current page.

Based on #500. Merge after the lower layers; no validation-PR dependency.

How to Test:

dotnet test WheelWizard.sln

582 tests passed (562 unit, 20 headless UI). Checks retain the same window/page/control instances, verify background-thread binding updates and disposal, and verify event forwarding when services change. Manually switch languages in settings and confirm focus/navigation state is preserved.

What Has Been Changed:

See the focused implementation above. The existing settings JSON contract and imported translation sheets are preserved.

Related Issue Link:

No linked issue. Part of native GitHub stack #503.

Checklist before merging

• You have created relevant tests

[coderabbitai]

Important

Draft PR not reviewed

Draft PRs are not automatically reviewed by default.

• Trigger a manual review

To automatically review draft PRs, update your CodeRabbit configuration:

reviews:
  auto_review:
    drafts: true

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}