Slice 2: telemetry, vitals, chat, spawn/portal, rare, kills and combat stats

The frames the backend reads most, each pinned by a golden test written from
the original's source (field order, JSON types, string-formatted numbers,
mem_mb in bytes, the PascalCase aggregates Newtonsoft emits for combat_stats).
Coordinates repeat the original's float arithmetic from the landblock-local
float, so ew/ns carry the same float-widened values as before. Telemetry goes
out on connect and every 5 s, vitals every 5 s, combat stats every 10 s when
dirty. The rare meta-state switch is not carried over (owner decision); the
allegiance rare announcement and the !report reply are. Kill patterns and
combat patterns are the original's, unchanged.

Also fixes the tick scheduler re-arming repeating jobs from now instead of
from their due time, which made every cadence drift a frame late per period.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/OpenAC.MosswartMassacre/Streams/TelemetryStream.cs

@@ -0,0 +1,84 @@
+using System.Globalization;
+using OpenAC.MosswartMassacre.Backend;
+using OpenAC.MosswartMassacre.Infrastructure;
+
+namespace OpenAC.MosswartMassacre.Streams;
+
+/// <summary>
+/// The <c>telemetry</c> frame: sent right after the socket registers and then
+/// every five seconds, as the original's socket loop did.
+/// </summary>
+/// <remarks>
+/// Several fields are strings on the wire (kill rate, deaths, taper count) and
+/// <c>mem_mb</c> carries bytes; the backend reads them that way.
+/// </remarks>
+internal sealed class TelemetryStream : IMmFeature, IBackendConnectionListener
+{
+    public static readonly TimeSpan Interval = TimeSpan.FromSeconds(5);
+
+    private readonly MmContext _context;
+    private readonly SessionStats _stats;
+    private readonly ProcessTelemetry _process = new();
+    private IDisposable? _timer;
+
+    public TelemetryStream(MmContext context, SessionStats stats)
+    {
+        _context = context;
+        _stats = stats;
+    }
+
+    public void OnBackendConnected()
+    {
+        if (!_context.IsLoggedIn)
+            return;
+        SendNow();
+        _timer?.Dispose();
+        _timer = _context.Scheduler.Every(Interval, SendNow);
+    }
+
+    public void OnLogin()
+    {
+    }
+
+    public void OnLogoff()
+    {
+        _timer?.Dispose();
+        _timer = null;
+    }
+
+    public void Dispose() => OnLogoff();
+
+    internal void SendNow()
+    {
+        if (!_context.IsLoggedIn)
+            return;
+        _context.Send(Build());
+    }
+
+    internal object Build()
+    {
+        MmCoordinates coords = MmCoordinates.From(_context.Automation.Navigation.Snapshot.Position);
+        var kills = _stats.Kills;
+        return new
+        {
+            type = "telemetry",
+            character_name = _context.CharacterName,
+            char_tag = _context.Settings.Current.CharTag ?? "",
+            session_id = MmContext.ProcessSessionId,
+            timestamp = Wire.Timestamp(_context.Clock),
+            ew = coords.EW,
+            ns = coords.NS,
+            z = coords.Z,
+            kills = kills.TotalKills,
+            kills_per_hour = kills.KillsPerHour.ToString("F0", CultureInfo.CurrentCulture),
+            onlinetime = (_context.Clock.Now - kills.StatsStartTime).ToString(@"dd\.hh\:mm\:ss", CultureInfo.InvariantCulture),
+            deaths = kills.SessionDeaths.ToString(CultureInfo.CurrentCulture),
+            total_deaths = kills.TotalDeaths.ToString(CultureInfo.CurrentCulture),
+            prismatic_taper_count = _context.PrismaticTaperCount().ToString(CultureInfo.CurrentCulture),
+            vt_state = _context.MetaState() ?? string.Empty,
+            mem_mb = _process.MemoryBytes,
+            cpu_pct = _process.SampleCpuUsage(),
+            mem_handles = _process.HandleCount,
+        };
+    }
+}