refactor!: rename the project from Monitor to MoShiro

Namespaces, assemblies, projects and directories, the solution, binaries,
images, systemd units, config paths, environment variables, protocol method
names, the media type and the raw chunk magic all move to MoShiro/moshiro.
Existing data and deployments are not compatible and must be recreated.
Also fix the architecture tests after the solution layout change and make
the update tests independent of their order.

backend/probe/tests/MoShiro.Probe.Tests/ProbeTests.cs

@@ -0,0 +1,85 @@
+using Fleet.Core;
+using Fleet.Hosting;
+using MoShiro.Protocol;
+
+namespace MoShiro.Probe.Tests;
+
+public sealed class ProbeTests
+{
+    [Fact]
+    public void ClockEstimator_UsesTheSampleWithTheShortestRoundTrip()
+    {
+        var clock = new ClockEstimator();
+        Assert.False(clock.HasEstimate);
+
+        // Offset 1000 with a 50 ms round trip, offset 5000 with a 2 ms round trip (symmetry assumption is far better here)
+        clock.Add(sendUs: 0, agentUs: 25_000 + 1000, receiveUs: 50_000);
+        clock.Add(sendUs: 100_000, agentUs: 101_000 + 5000, receiveUs: 102_000);
+        Assert.True(clock.HasEstimate);
+        Assert.Equal(5000, clock.OffsetUs);
+
+        // Slow samples do not displace the good one
+        clock.Add(sendUs: 200_000, agentUs: 300_000, receiveUs: 400_000);
+        Assert.Equal(5000, clock.OffsetUs);
+    }
+
+    private static string NewDirectory()
+    {
+        string path = Path.Combine(Path.GetTempPath(), "probe-tests-" + Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(path);
+        return path;
+    }
+
+    private static ProbeAgentList List(long version, params string[] ids) => new()
+    {
+        Version = version,
+        Agents = [.. ids.Select(id => new AgentEndpoint { AgentId = new NodeId(id), Host = id + ".example", TcpPort = 7443, Spki = "c3BraQ==" })],
+    };
+
+    [Fact]
+    public void AgentDirectory_StartsEmpty_IgnoresStaleLists_PersistsChanges_AndReloadsThem()
+    {
+        string directory = NewDirectory();
+        try
+        {
+            var directoryA = new AgentDirectory(new ConfigStore(directory), directory, NullNodeLog.Instance);
+            int changes = 0;
+            directoryA.Changed += () => changes++;
+            Assert.Empty(directoryA.Agents);
+
+            directoryA.Apply(List(5, "agt_1", "agt_2"));
+            Assert.Equal(1, changes);
+            Assert.Equal(["agt_1", "agt_2"], directoryA.Agents.Select(a => a.AgentId));
+
+            directoryA.Apply(List(4, "agt_old")); // out-of-order older push
+            directoryA.Apply(List(5, "agt_1", "agt_2")); // same version and content
+            Assert.Equal(1, changes);
+            Assert.Equal(5, directoryA.Version);
+
+            // The next start uses the saved list while the panel is not reachable yet
+            var directoryB = new AgentDirectory(new ConfigStore(directory), directory, NullNodeLog.Instance);
+            Assert.Equal(["agt_1", "agt_2"], directoryB.Agents.Select(a => a.AgentId));
+            Assert.Equal(5, directoryB.Version);
+        }
+        finally
+        {
+            Directory.Delete(directory, recursive: true);
+        }
+    }
+
+    [Fact]
+    public void AgentDirectory_StartsEmpty_WhenTheSavedFileIsCorrupt()
+    {
+        string directory = NewDirectory();
+        try
+        {
+            new ConfigStore(directory).Write(AgentDirectory.FileName, "{ not json"u8.ToArray());
+            var loaded = new AgentDirectory(new ConfigStore(directory), directory, NullNodeLog.Instance);
+            Assert.Empty(loaded.Agents);
+        }
+        finally
+        {
+            Directory.Delete(directory, recursive: true);
+        }
+    }
+}