fix(launcher): truncate download status labels to stop progress dialog blowout

[localai-bot]

Fixes #10355

Problem

In the desktop launcher, the download progress dialog grows too wide and the progress bar stretches "to infinity" when a download fails. The width grows in proportion to the length of the Download failed: … message.

Root cause

The launcher is a Fyne app. Each download progress window places a widget.ProgressBar and a status widget.Label in the same VBox. On failure the status label is set to "Download failed: <error>", and the error commonly contains a long, unbreakable URL/path. A Fyne label with default settings reports its MinSize as the full single-line text width, so a long message forces the window — and the progress bar sharing the VBox — arbitrarily wide.

Fix

Set Truncation = fyne.TextTruncateEllipsis on the four affected status labels:

• the main-window status label (NewLauncherUI), which UpdateStatus sets to "Failed to download update: <error>", and
• the status label in each of the three showDownloadProgress implementations (ui.go, launcher.go, systray_manager.go).

With ellipsis truncation, the label's MinSize collapses to roughly one character plus the ellipsis regardless of content, so the window keeps its intended 400×250 size. TextWrapWord is not sufficient because it cannot break a spaceless URL. The full error text remains visible via the dialog.ShowError call already present in each code path.

Testing

• gofmt clean; fyne.TextTruncateEllipsis matches the widget.Label.Truncation field type (mirrors the existing welcomeLabel.Wrapping = fyne.TextWrapWord usage in the same file).
• Full launcher compile requires GL/X11 dev headers (Fyne CGO deps) not available in my environment; please confirm via make build-launcher in CI.

Assisted-by: Claude:claude-opus-4-8 [Claude Code]