feat(clients): Wake-on-LAN in apple/linux/windows/android/decky

Each client learns a host's MAC from the mDNS `mac` TXT while it's awake, persists it on the saved-host record, and — when reconnecting to an offline host — sends a magic packet before connecting, plus an explicit "Wake host" action. Apple wraps the C-ABI; linux/windows call the core fn directly (linux also gains a --wake CLI mode); android via a new nativeWakeOnLan JNI export (the mDNS browse record gains a 7th mac field); decky shells out to the linux client's --wake before launching the stream.

iOS/tvOS need the managed com.apple.developer.networking.multicast entitlement (pending Apple approval), so the wake path + UI are gated off via PunktfunkConnection.wakeOnLANAvailable and the entitlement is commented out — keeping iOS/tvOS releasable. MAC-learning stays active on every platform so it lights up the moment it's ungated. macOS works today.

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

clients/apple/Sources/PunktfunkClient/Home/HostCards.swift

@@ -86,6 +86,9 @@ struct HostCardView: View {
     let onRemove: () -> Void
     /// Open the experimental library browser — nil (no menu item) unless the feature flag is on.
     var onBrowseLibrary: (() -> Void)? = nil
+    /// Send a Wake-on-LAN magic packet. Shown only when the host is offline and we have a stored
+    /// MAC to target (a tap-to-connect already auto-wakes; this is the explicit "just wake it").
+    var onWake: (() -> Void)? = nil
 
     var body: some View {
         let m = CardMetrics.current
@@ -138,6 +141,9 @@ struct HostCardView: View {
             if let onBrowseLibrary {
                 Button("Browse Library…", action: onBrowseLibrary)
             }
+            if !isOnline, !host.wakeMacs.isEmpty, PunktfunkConnection.wakeOnLANAvailable, let onWake {
+                Button("Wake Host", systemImage: "power", action: onWake)
+            }
             if host.pinnedSHA256 != nil {
                 // Dropping the pin does NOT downgrade to TOFU: the next connect must re-pair via
                 // PIN (unless the host advertises pair=optional). Wording reflects that.