iOS: the player goes to ipxapi.sdf1.net with one API token; unread badge (#419, #421)

The Access service token plus API token pair was three values to enter
and Access in front of both. The player, the badge and CarPlay now send
the ipx API token alone to https://ipxapi.sdf1.net: a route of the
rays-unraid tunnel to the same ipx-web, with no Access application, held
to the paths the app uses by a custom firewall rule on the sdf1.net zone
(403 for anything without a bearer header or off the list: the page, the
login form, /api/login, ?token= sign-in, the admin API). docs/sso.md
says so, since it also says not to bypass Access for /api/*; this is
that warning's narrow version, and the rule is on Cloudflare, not here.

The unread badge (#421) shows All Subscriptions' count, as the page's
badge does: set when the app comes forward, after an item is read, and
by a background refresh iOS runs now and then. The test target had no
Info.plist and could never have run; it does now.

Build 4. Not yet run on a phone with the token set.

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

ios/Sources/Server.swift

@@ -40,4 +40,22 @@ enum Server {
         guard let base = url else { return nil }
         return URL(string: path, relativeTo: base)?.absoluteURL
     }
+
+    /// Where the player, the badge and CarPlay talk to ipx, which is not where the page is: an
+    /// address with no Cloudflare Access in front, for the API token alone (#419). Always https,
+    /// since the token travels in a header.
+    private static let apiKey = "ipx.api"
+    static let suggestedAPI = "https://ipxapi.sdf1.net"
+
+    static var apiURL: URL? {
+        get { UserDefaults.standard.string(forKey: apiKey).flatMap(normalise).flatMap { $0.scheme == "https" ? $0 : nil } }
+        set { UserDefaults.standard.set(newValue?.absoluteString, forKey: apiKey) }
+    }
+
+    /// A path against the player's address when there are credentials to send there, else the
+    /// page's, where the web view's cookie does the signing in.
+    static func resolveForPlayer(_ path: String) -> URL? {
+        guard Credentials.isSet, let base = apiURL else { return resolve(path) }
+        return URL(string: path, relativeTo: base)?.absoluteURL
+    }
 }