macos: investigate accessibilityLiveRegion API resolution failure on macos-15 runner

[Salem874]

Background

Follow-up to #145. ServerView.swift previously called:

```swift
Text(model.status.displayText)
.accessibilityLabel("Server status: (model.status.displayText)")
.accessibilityLiveRegion(.polite)
```

This failed to compile on the GitHub Actions macos-15 runner with:

• `error: value of type 'Text' has no member 'accessibilityLiveRegion'`
• `error: cannot infer contextual base in reference to member 'polite'`

Despite `Package.swift` declaring `platforms: [.macOS(.v15)]` and `accessibilityLiveRegion(_:)` being documented as available on macOS 14.0+.

#145 applied a pragmatic fix: drop the line with a TODO so other CI failures could be addressed. This issue tracks the proper investigation + restoration of the live-region announcement.

Investigation TODO

• Reproduce locally on a macOS 15 dev machine with Xcode matching the macos-15 runner.
• Check Xcode version on macos-15 runner via `xcode-select -p && xcodebuild -version` step.
• Determine whether the issue is: SDK skew (runner SDK behind), Swift 6 strict-type-inference quirk, or modifier needs explicit `View` extension import.
• Apply correct fix (e.g. explicit `AccessibilityLiveRegion.polite`, or version guard, or use of a different API).
• Remove the TODO comment in `ServerView.swift` and restore the live-region announcement.
• Verify CI passes on macos-15.

Accessibility impact while open

Server status changes are still announced via `accessibilityLabel` (read on focus) — only the automatic live-region announcement on status change is missing. Users who keep focus on the status indicator won't notice; users navigating away during an operation won't hear status updates without re-focusing.

[Salem874]

Update from PR #144 iteration 4

Bumped Package.swift to swift-tools-version 6.3 and switched ci-macos.yml to the macos-26 runner (Xcode 26.4.1 / Swift 6.3). Hypothesis was that the API would resolve on the newer SDK.

Result: it still doesn't. Error persists:

error: value of type 'Text' has no member 'accessibilityLiveRegion'
error: cannot infer contextual base in reference to member 'polite'

Root cause (corrected)

accessibilityLiveRegion is a UIKit / AppKit UIAccessibility property, NOT a SwiftUI View modifier. It was never available on SwiftUI's Text / View. The original code was mistakenly written as if SwiftUI exposed parity with UIKit's accessibility API — which it doesn't.

What PR #144 ships

Removed the 5 .accessibilityLiveRegion(.polite) calls (final — they don't and won't compile). The status text is still announced via accessibilityLabel, which works correctly.

Proper future fix

For actual live-region announcements in SwiftUI, the documented patterns are:

• AccessibilityNotification.Announcement.post(...) for one-shot status announcements when state changes
• Or move to a UIKit/AppKit interop via UIViewRepresentable / NSViewRepresentable if direct UIAccessibility integration is needed

Closing this issue as "wontfix in its original form". A separate, scope-clear issue should be filed if/when accessibility-announcement work is prioritised.