chore(apple/M1): move widget sources into the Xcode target's synced folder

Xcode created the PunktfunkWidgetsExtension target with a file-system-
synchronized root group at clients/apple/PunktfunkWidgets/, so the target
compiles whatever lives there. Deleted the three generated stubs
(PunktfunkWidgets.swift / PunktfunkWidgetsBundle.swift /
PunktfunkWidgetsControl.swift — the stub @main WidgetBundle would collide with
ours) and moved our sources (PunktfunkWidgetBundle / HostsWidget /
SessionLiveActivity) from Sources/PunktfunkWidgets/ into PunktfunkWidgets/. Kept
the generated Info.plist (build-excluded via the sync exception set) and
Assets.xcassets. Still outside Sources/, so SwiftPM ignores it; swift build green.

project.pbxproj is intentionally NOT part of this commit — the target's
capability/signing edits (step 3) are still in progress in Xcode.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

clients/apple/PunktfunkWidgets/PunktfunkWidgetBundle.swift

@@ -0,0 +1,20 @@
+// The widget extension's entry point. ONE extension target (bundle id io.unom.punktfunk.widgets,
+// iOS only) hosts both the launcher widgets and the Live Activity UI. It links PunktfunkShared and
+// NOTHING else — never PunktfunkKit (Rust staticlib + presentation layer would blow the widget
+// process's ~30 MB budget).
+//
+// These files are NOT part of the SwiftPM package (Package.swift doesn't declare a PunktfunkWidgets
+// target, so `swift build` ignores the directory). They compile only in the Xcode widget-extension
+// target you add pointing at this folder — see design/apple-live-activities-and-widgets.md §M1 and
+// the GUI checklist.
+
+import SwiftUI
+import WidgetKit
+
+@main
+struct PunktfunkWidgetBundle: WidgetBundle {
+    var body: some Widget {
+        HostsWidget()
+        PunktfunkSessionLiveActivity()
+    }
+}