fix(network): advertise 127.0.0.1 instead of localhost in playlist URL

Build 122 overlay showed AVPlayer in `timeControlStatus=waitingToPlay
reason=AVPlayerWaitingWhileEvaluatingBufferingRateReason` but zero
`[HLSLocalServer] conn state=…` lines, even though that handler now
fires the moment any TCP connection arrives at the listener
(`.preparing` / `.ready` / `.failed` / `.cancelled`). The only way
that's consistent: AVPlayer never actually opens a socket to
localhost:port. It's hanging upstream of TCP, on hostname
resolution.

The original comment claimed `localhost` was needed for tvOS ATS
to treat the connection as exempt without a per-domain plist
entry. That's moot on the consumer side: Sodalite's Info.plist
already has both `NSAllowsArbitraryLoads` and
`NSAllowsLocalNetworking`, so any HTTP loopback is allowed
regardless of host form. The IP literal `127.0.0.1` sidesteps
the DNS / nsswitch / /etc/hosts resolution path AVKit appears to
hang in.

If this lands the connection, the next overlay screenshot will
show the burst of `[HLSLocalServer] conn state=ready` plus a
`GET /master.m3u8` line within a frame of `play()`. If AVPlayer
still hangs after this we know DNS wasn't the cause and can
chase the next suspect (codec-string strictness, asset
pre-flight) without DNS muddying the signal.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: superuser404notfound

Sources/AetherEngine/Network/HLSLocalServer.swift

@@ -113,10 +113,23 @@ final class HLSLocalServer: @unchecked Sendable {
     /// URL the host hands to AVPlayer to start playback. Points at
     /// the master playlist if the provider has one, else the media
     /// playlist directly.
+    ///
+    /// Uses the IP literal `127.0.0.1` rather than the hostname
+    /// `localhost`. The hostname form needs DNS / nsswitch /
+    /// /etc/hosts to resolve, and AVPlayer on tvOS appears to hang
+    /// in its pre-flight before opening any TCP socket when
+    /// resolution doesn't return immediately (build 122
+    /// `timeControlStatus=waitingToPlay` with zero NWListener
+    /// state-update events). The IP literal sidesteps the resolver
+    /// entirely. ATS is covered either way: Sodalite's Info.plist
+    /// already has `NSAllowsArbitraryLoads` plus
+    /// `NSAllowsLocalNetworking`, so the original argument for
+    /// keeping the hostname (per-domain ATS exception avoidance)
+    /// no longer applies.
     var playlistURL: URL? {
         guard port > 0 else { return nil }
         let path = (provider?.masterCodecs != nil) ? "master.m3u8" : "media.m3u8"
-        return URL(string: "http://localhost:\(port)/\(path)")
+        return URL(string: "http://127.0.0.1:\(port)/\(path)")
     }
 
     // MARK: - Init