Plexamp Lite 1.13: read ahead the next two tracks, keep loaded roots

Read-ahead keeps the next two tracks on the SD card (one without it) and drops files
that are no longer coming up. Trusted roots are cached once read, and a failed read
is retried instead of leaving every server untrusted until a restart.

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

test/QueueTest.java

@@ -25,6 +25,12 @@ public class QueueTest {
         return sb.toString().trim();
     }
 
+    static String titles(List<Item> l) {
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < l.size(); i++) sb.append(i > 0 ? " " : "").append(l.get(i).title);
+        return sb.toString();
+    }
+
     public static void main(String[] a) {
         PlayQueue q = PlayQueue.get();
         q.set(tracks(5), 2, false, "Album");
@@ -65,6 +71,18 @@ public class QueueTest {
         check(q.size() == 10 && q.index() == 0 && q.shuffle(), "shuffle play from random start");
         q.clear();
         check(q.current() == null && q.size() == 0, "clear");
+        // read-ahead window: the next two tracks, wrapping only with repeat all, never the current one
+        q.set(tracks(4), 1, false, "Ahead");
+        check(titles(q.peekAhead(2)).equals("T2 T3"), "peekAhead 2 from T1: " + titles(q.peekAhead(2)));
+        q.advance(false); q.advance(false);
+        check(titles(q.peekAhead(2)).equals(""), "peekAhead at the end, repeat off: empty");
+        q.cycleRepeat(); // all
+        check(titles(q.peekAhead(2)).equals("T0 T1"), "peekAhead wraps with repeat all: " + titles(q.peekAhead(2)));
+        q.cycleRepeat(); q.cycleRepeat(); // off
+        q.set(tracks(2), 0, false, "Two");
+        q.cycleRepeat(); // all
+        check(titles(q.peekAhead(2)).equals("T1"), "peekAhead skips the current track on wrap: " + titles(q.peekAhead(2)));
+        q.cycleRepeat(); q.cycleRepeat(); // off
         System.out.println(fails == 0 ? "ALL PASSED" : fails + " FAILED");
         System.exit(fails == 0 ? 0 : 1);
     }