feat(app): Add navigation buttons to electron desktop

[omstr]

Summary

Small PR adds electron app nav buttons to the native titlebar. I decided my placement was the "cleanest" for me, but they both could also go before the Fluxer Wordmark, or, one on each side (i prefer them to be close together) etc.

• What changed:
  • Commit 1:
    • fluxer_app/src/features/app/components/layout/Added React component NativeTitlebarNav.tsx & it's css file
    • fluxer_app/features/ui/utils Added type NativeTitlebarNavOptions
    • fluxer_app/src/features/app/components/layout/ Added new NativeTitlebarNav react component to NativeTitlebar
  • Commit 2 & 3 - merging & undoing local changes i accidentally pushed
  • Commit 4: Navigation adapter additions to monitor ability to go forwards
    • fluxer_app/src/features/platform/components/router/NavigationAdapter.ts canGoForward and onCanGoForwardChange methods added
    • fluxer_app/src/features/platform/components/router/BrowserNavigation.ts canGoForward added to interface
    • NativeTitlebarNav.tsx Added stuff to do event propagation properly in React and add a watcher to the forward nav button to grey it out if needed.
    • NativeTitlebar.tsx removed my own previously 2 redundant props.
• Why it is correct:
  • It wasn't possible to navigate forwards & backwards via the UI, so I wanted to add some back/forward functionality to the UI of the native app. It works & it'll grey out the buttons if they'll do nothing.
• Risk: None

Verification

• Tests run:

  • pnpm test inside fluxer_app
  • results:
    • Test Files 211 passed (211)
    • Tests 1616 passed (1616)
    • Start at 15:52:51
    • Duration 7.41s (transform 18.77s, setup 0ms, import 56.43s, tests 11.46s, environment 2.19s)

• Manual checks:

  • Forwards/backwards tests worked
  • Buttons grey out as expected

• Screenshots or recordings:

Screencast_20260729_155028.mp4

Checklist

• I understand every change in this PR.
• I can explain what it does and why it is correct.
• I disclosed any LLM coding help below.

LLM Disclosure

• LLMs helped me understand how to do some Vue things in React