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/Stores/HostStore.swift

@@ -26,9 +26,16 @@ struct StoredHost: Identifiable, Codable, Hashable {
     /// decode: synthesized Decodable ignores property defaults but treats a missing Optional as
     /// nil. Resolve via `effectiveMgmtPort`. (Auth is mTLS by the pinned identity — no token.)
     var mgmtPort: UInt16?
+    /// Wake-on-LAN MAC address(es) of the host's wake-capable NIC(s), each `aa:bb:cc:dd:ee:ff`.
+    /// Learned from the host's mDNS `mac` TXT record while it's awake and persisted here, so the
+    /// client can send a magic packet to wake the host later (when it's asleep and no longer
+    /// advertising). Optional (same forward-compat reason as `mgmtPort`); nil until first learned.
+    var macAddresses: [String]?
 
     var displayName: String { name.isEmpty ? address : name }
     var effectiveMgmtPort: UInt16 { mgmtPort ?? punktfunkDefaultMgmtPort }
+    /// Wake-capable, in a form the wake helper accepts (empty when none learned yet).
+    var wakeMacs: [String] { macAddresses ?? [] }
 }
 
 extension StoredHost {
@@ -101,6 +108,16 @@ final class HostStore: ObservableObject {
         hosts[i].pinnedSHA256 = fingerprint
     }
 
+    /// Learn/refresh this host's Wake-on-LAN MAC(s) from its live advert (called while the host is
+    /// awake, so the client can wake it once it sleeps). No-op when unchanged, so it doesn't churn
+    /// UserDefaults on every discovery tick.
+    func updateMacs(_ hostID: UUID, macs: [String]) {
+        guard !macs.isEmpty,
+              let i = hosts.firstIndex(where: { $0.id == hostID }),
+              hosts[i].macAddresses != macs else { return }
+        hosts[i].macAddresses = macs
+    }
+
     /// Drop the pinned identity (e.g. after a legitimate host reinstall). This does NOT downgrade
     /// to TOFU: the next connect re-pairs via the PIN ceremony, unless the host advertises
     /// `pair=optional` (the only case the connect path still offers the trust prompt).