Fix: make AutoRelog retries single-owner (#3186)

Login rejections could schedule and execute multiple restarts for one failure while leaving no usable console route during reconnect delays.

Changes:
- Bind failure and restart work to immutable connection attempts
- Coalesce automatic retries while allowing explicit settings replacement until commit
- Preserve held bots and offline command routing across failed logins
- Add deterministic retry, ownership, and routing regression tests

Fixes #3186

MinecraftClient.Tests/AutoRelogRetryPolicyTests.cs

@@ -62,6 +62,37 @@ public sealed class AutoRelogRetryPolicyTests
         Assert.Equal(0, retriesLeft);
     }
 
+    [Fact]
+    public void CoalescedDuplicateRollsBackOnlyItsOwnReservation()
+    {
+        var policy = new AutoRelogRetryPolicy(new ManualTimeProvider());
+
+        Assert.True(policy.TryReserveAttempt(2, out int firstRetriesLeft));
+        Assert.True(policy.TryReserveAttempt(2, out int duplicateRetriesLeft));
+        policy.RollBackReservedAttempt();
+
+        Assert.Equal(1, firstRetriesLeft);
+        Assert.Equal(0, duplicateRetriesLeft);
+        Assert.Equal(1, policy.Attempts);
+        Assert.True(policy.TryReserveAttempt(2, out int secondFailureRetriesLeft));
+        Assert.Equal(0, secondFailureRetriesLeft);
+        Assert.False(policy.TryReserveAttempt(2, out _));
+    }
+
+    [Fact]
+    public void UnlimitedDuplicateRollbackKeepsUnlimitedBudget()
+    {
+        var policy = new AutoRelogRetryPolicy(new ManualTimeProvider());
+
+        Assert.True(policy.TryReserveAttempt(-1, out _));
+        Assert.True(policy.TryReserveAttempt(-1, out _));
+        policy.RollBackReservedAttempt();
+
+        Assert.Equal(1, policy.Attempts);
+        Assert.True(policy.TryReserveAttempt(-1, out int retriesLeft));
+        Assert.Equal(-1, retriesLeft);
+    }
+
     [Fact]
     public void StableConnectionResetsRetryBudget()
     {