iOS 1.0 RC 2: Plex streams under upload caps, shuffle and album radio stations, Recently Added list, photo covers, crossfade

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ios/Stemify/Plex/PlexServer.swift

@@ -317,6 +317,32 @@ final class PlexServer: MediaSource, @unchecked Sendable {
         URL(string: base + partKey + "?X-Plex-Token=" + urlEncode(token))
     }
 
+    /// The part's URL the way Plexamp plays it: first a playback decision for this session, then
+    /// the file fetched under that session and client. A bare part request has no bitrate, so Plex
+    /// reads it as unlimited ("Bandwidth exceeded: 2147483647 kbps") and answers 500 whenever
+    /// Remote Access has an upload limit set.
+    func streamUrl(_ ratingKey: String, partKey: String) async -> URL? {
+        let session = UUID().uuidString.lowercased()
+        if signedIn, let u = try? url("/music/:/transcode/universal/decision", [
+            ("path", "/library/metadata/\(ratingKey)"), ("mediaIndex", 0), ("partIndex", 0),
+            ("protocol", "http"), ("directPlay", 1), ("directStream", 1), ("directStreamAudio", 1),
+            ("hasMDE", 1), ("session", session), ("X-Plex-Session-Identifier", session),
+        ]) {
+            var req = request(u)
+            req.setValue(session, forHTTPHeaderField: "X-Plex-Session-Identifier")
+            req.timeoutInterval = 8
+            // Best effort: the part URL below still carries the session if this fails.
+            if let (_, resp) = try? await http.session.data(for: req), let code = (resp as? HTTPURLResponse)?.statusCode, code >= 300 {
+                Log.shared.error("plex", "stream decision for \(ratingKey): HTTP \(code)")
+            }
+        }
+        guard let u = URL(string: base + partKey) else { return nil }
+        return u.with([
+            ("X-Plex-Token", token), ("X-Plex-Client-Identifier", settings.clientId), ("X-Plex-Product", Self.product),
+            ("X-Plex-Platform", "iOS"), ("X-Plex-Device", model), ("X-Plex-Session-Identifier", session), ("session", session),
+        ])
+    }
+
     // ---- plex.tv sign-in ------------------------------------------------------------
 
     func createPin() async throws -> PlexPin {