[client] Fix Advanced Settings not opening on Windows with Japanese locale (#4455)

[h6ah4i]

The Fyne framework does not support TTC font files. Use the default system font (Segoe UI) instead, so Windows can automatically fall back to a Japanese font when needed.

Describe your changes

Stop specifying Yugothm.ttc for Japanese locale.

The same fix has been introduced to v0.39.1 for Chinese locale; A-Archives-and-Forks@4508c61

Issue ticket number and link

• Advanced settings cannot be opened when the language is set to Japanese #4455

Stack

Checklist

• Is it a bug fix
• Is a typo/documentation fix
• Is a feature enhancement
• It is a refactor
• Created tests that fail without the change (if possible)

By submitting this pull request, you confirm that you have read and agree to the terms of the Contributor License Agreement.

Documentation

Select exactly one:

• I added/updated documentation for this change
• Documentation is not needed for this change (explain why)

This is just a bug fix which does not change the current product spec.

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This is a screenshot for verifying automatic Japanese font fall back is working. (this change is not committed)

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Crash log:

2025/10/14 19:13:30 Fyne error:  font load error
2025/10/14 19:13:30   Cause: collections not allowed
2025/10/14 19:13:30   At: C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/internal/painter/font.go:197
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x0 pc=0x7ff73b389344]

goroutine 1 [running, locked to thread]:
fyne.io/fyne/v2/internal/painter.(*dynamicFontMap).ResolveFace(0xc003ce27e0, 0x20)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/internal/painter/font.go:362 +0x64
fyne.io/fyne/v2/internal/painter.walkString({0x7ff73c761840, 0xc003ce27e0}, {0xc000202f04?, 0x0?}, 0x380, {0x0, 0x0, 0x0, 0x0, 0x0, ...}, ...)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/internal/painter/font.go:256 +0xb9
fyne.io/fyne/v2/internal/painter.MeasureString({0x7ff73c761840?, 0xc003ce27e0?}, {0xc000202f04?, 0x0?}, 0x0?, {0x0, 0x0, 0x0, 0x0, 0x0, ...})
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/internal/painter/font.go:207 +0x6e
fyne.io/fyne/v2/internal/painter.measureText({0xc000202f04, 0x0}, 0x41600000, {0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, {0x0, ...})
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/internal/painter/font.go:233 +0xa5
fyne.io/fyne/v2/internal/painter.RenderedTextSize({0xc000202f04, 0x0}, 0x41600000, {0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, {0x0, ...})
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/internal/painter/font.go:218 +0xf8
fyne.io/fyne/v2/internal/driver/glfw.(*gLDriver).RenderedTextSize(0x0?, {0xc000202f04?, 0x7ff73b3b69ae?}, 0x3c58f162?, {0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, ...)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/internal/driver/glfw/driver.go:72 +0x7f
fyne.io/fyne/v2.MeasureText({0xc000202f04, 0x0}, 0x41600000, {0x0, 0x0, 0x0, 0x0, 0x0, 0x0})
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/text.go:72 +0x98
fyne.io/fyne/v2/widget.(*RichText).updateRowBounds.func1({0xc000205be0?, 0x7ff73c5a51e9?, 0x0?})
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/widget/richtext.go:481 +0x892
fyne.io/fyne/v2/widget.(*RichText).updateRowBounds(0xc00036ed38)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/widget/richtext.go:495 +0x1f0
fyne.io/fyne/v2/widget.(*entryRenderer).Refresh(0xc000210640)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/widget/entry.go:1811 +0xcf
fyne.io/fyne/v2/widget.(*BaseWidget).Refresh(0xc00036ec08)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/widget/widget.go:137 +0x9d
fyne.io/fyne/v2/widget.(*Entry).Refresh(0xc00036ec08)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/widget/entry.go:488 +0x52
fyne.io/fyne/v2/widget.(*DisableableWidget).Disable(0xc00036ec08?)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/widget/widget.go:207 +0x4e
fyne.io/fyne/v2/widget.(*Entry).Disable(...)
        C:/Users/******/go/pkg/mod/fyne.io/fyne/v2@v2.5.3/widget/entry.go:225
main.(*serviceClient).showSettingsUI(0xc00045e708)
        C:/Users/******/git/netbird/client/ui/client_ui.go:414 +0x225
main.newServiceClient(0xc000237ee0)
        C:/Users/******/git/netbird/client/ui/client_ui.go:342 +0x23d
main.main()
        C:/Users/******/git/netbird/client/ui/client_ui.go:88 +0x250
2025-10-14T19:13:30+09:00 INFO client/ui/event_handler.go:228: command 'settings true' failed with exit code 2

[CLAassistant]

All committers have signed the CLA.

[Copilot]

Pull Request Overview

This PR fixes an issue where the Advanced Settings dialog would not open on Windows systems with Japanese locale due to the Fyne framework's incompatibility with TTC font files. The fix removes the explicit Japanese font specification to allow Windows to automatically fall back to appropriate fonts.

• Removes the explicit "Yugothm.ttc" font specification for Japanese locale ("ja-JP")
• Allows Windows to use the default system font (Segoe UI) and automatically fall back to Japanese fonts when needed
• Aligns with a similar fix previously applied for Chinese locale in v0.39.1

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[h6ah4i]

@lixmal Hi! Could you take a look at this change?
It fixes an issue affecting Japanese users, including us. Thank you! 🙇