iOS: stem playlist refresh and covers, download queue page, reorderable Library, whole-library radio

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

ios/Stemify/Plex/PlexServer.swift

@@ -325,6 +325,46 @@ final class PlexServer: MediaSource, @unchecked Sendable {
         return try JSONDecoder().decode(PlexPin.self, from: try await http.data(req))
     }
 
+    /// A strong PIN, completed in the browser at [authUrl] (same flow as the web UI).
+    func createStrongPin() async throws -> PlexPin {
+        var req = request(URL(string: "https://plex.tv/api/v2/pins?strong=true")!, withToken: false, method: "POST")
+        req.httpBody = Data()
+        return try JSONDecoder().decode(PlexPin.self, from: try await http.data(req))
+    }
+
+    func authUrl(code: String) -> URL? {
+        var c = URLComponents(string: "https://app.plex.tv/auth")
+        c?.percentEncodedFragment = "?clientID=\(urlEncode(settings.clientId))&code=\(urlEncode(code))&context%5Bdevice%5D%5Bproduct%5D=\(urlEncode(Self.product))"
+        return c?.url
+    }
+
+    /// Every server this plex.tv account can reach, owned or shared.
+    func resources(token: String) async throws -> [PlexResource] {
+        var req = request(URL(string: "https://plex.tv/api/v2/resources?includeHttps=1&includeRelay=1")!, withToken: false)
+        req.setValue(token, forHTTPHeaderField: "X-Plex-Token")
+        let list = try JSONDecoder().decode([Lenient<PlexResource>].self, from: try await http.data(req))
+        return list.compactMap(\.value).filter(\.isServer)
+    }
+
+    /// The first address that answers /identity as the expected server, local ones first, relay last.
+    func reach(_ r: PlexResource, userToken: String) async -> String? {
+        let tok = r.accessToken.isEmpty ? userToken : r.accessToken
+        let ordered = r.connections.filter { !$0.uri.isEmpty }.sorted { rank($0) < rank($1) }
+        for c in ordered {
+            let base = c.uri.trimmingCharacters(in: CharacterSet(charactersIn: "/"))
+            guard let u = URL(string: base + "/identity") else { continue }
+            var req = request(u, withToken: false)
+            req.setValue(tok, forHTTPHeaderField: "X-Plex-Token")
+            req.timeoutInterval = 3.5
+            guard let body = try? await http.data(req),
+                  let id = try? decode(body).machineIdentifier, id == r.clientIdentifier || r.clientIdentifier.isEmpty else { continue }
+            return base
+        }
+        return nil
+    }
+
+    private func rank(_ c: PlexResource.Connection) -> Int { c.relay ? 2 : (c.local ? 0 : 1) }
+
     func checkPin(_ id: Int64) async throws -> PlexPin {
         let req = request(URL(string: "https://plex.tv/api/v2/pins/\(id)")!, withToken: false)
         return try JSONDecoder().decode(PlexPin.self, from: try await http.data(req))