refactor!: rename the project from Monitor to MoShiro [CI]

Namespaces, assemblies, solution, binaries, images, systemd units, config paths, environment variables, protocol methods and the Linux user are all renamed. Breaking: existing databases, node identities and installed units must be recreated.

backend/src/MoShiro.Backend.Application/Live/HotLayer.cs

@@ -0,0 +1,144 @@
+using System.Collections.Concurrent;
+using Fleet.Core;
+using MoShiro.Backend.Analysis;
+using MoShiro.Protocol;
+
+namespace MoShiro.Backend.Application;
+
+/// <summary>
+/// 1 秒精度的内存热层：最近 1 小时的累加器。桶以 <see cref="AccumulatorCodec"/> 编码后的字节保存，
+/// 15 条线路约十几 MB；它同时是 SSE 实时推送的数据来源。重启后为空，由后台任务从原始块回填。
+/// </summary>
+public sealed class HotLayer
+{
+    public const long BucketMs = 1000;
+    public static readonly TimeSpan Retention = TimeSpan.FromHours(1);
+
+    private readonly ConcurrentDictionary<(NodeId Agent, string Series), Ring> _rings = new();
+    private readonly TimeProvider _time;
+    private volatile bool _ready;
+
+    public HotLayer(TimeProvider time)
+    {
+        _time = time;
+    }
+
+    /// <summary>回填完成之前热层不完整，查询规划器不会选用它。</summary>
+    public bool Ready => _ready;
+
+    public void MarkReady() => _ready = true;
+
+    public IEnumerable<(NodeId Agent, string Series)> Keys => _rings.Keys;
+
+    /// <summary>评估一个块并合并进热层。同一个块重复合并（例如回填与实时竞争）会被忽略。</summary>
+    public void Merge(NodeId agent, string series, RawChunk chunk)
+    {
+        Ring ring = _rings.GetOrAdd((agent, series), _ => new Ring());
+        var buckets = new SortedDictionary<long, MetricSet>();
+        WindowEvaluator.Default.Evaluate(chunk, BucketMs, buckets);
+        long cutoff = _time.GetUtcNow().ToUnixTimeMilliseconds() - (long)Retention.TotalMilliseconds;
+        lock (ring)
+        {
+            if (!ring.Chunks.Add(chunk.Header.ChunkId))
+            {
+                return;
+            }
+
+            foreach ((long start, MetricSet set) in buckets)
+            {
+                if (start < cutoff)
+                {
+                    continue;
+                }
+
+                if (ring.Buckets.TryGetValue(start, out byte[]? existing) && AccumulatorCodec.Decode(existing).TryGet(out MetricSet? merged, out _))
+                {
+                    merged.Merge(set);
+                    ring.Buckets[start] = AccumulatorCodec.Encode(merged);
+                }
+                else
+                {
+                    ring.Buckets[start] = AccumulatorCodec.Encode(set);
+                }
+            }
+
+            Prune(ring, cutoff);
+        }
+    }
+
+    /// <summary>[from, to) 内的 1 秒桶（解码后的副本，按时间升序）。</summary>
+    public IReadOnlyList<KeyValuePair<long, MetricSet>> GetRange(NodeId agent, string series, long fromMs, long toMs)
+    {
+        if (!_rings.TryGetValue((agent, series), out Ring? ring))
+        {
+            return [];
+        }
+
+        var result = new List<KeyValuePair<long, MetricSet>>();
+        lock (ring)
+        {
+            foreach ((long start, byte[] bytes) in ring.Buckets)
+            {
+                if (start >= toMs)
+                {
+                    break;
+                }
+
+                if (start >= fromMs && AccumulatorCodec.Decode(bytes).TryGet(out MetricSet? set, out _))
+                {
+                    result.Add(new KeyValuePair<long, MetricSet>(start, set));
+                }
+            }
+        }
+
+        return result;
+    }
+
+    public int BucketCount(NodeId agent, string series)
+    {
+        if (!_rings.TryGetValue((agent, series), out Ring? ring))
+        {
+            return 0;
+        }
+
+        lock (ring)
+        {
+            return ring.Buckets.Count;
+        }
+    }
+
+    public void Remove(NodeId agent)
+    {
+        foreach ((NodeId Agent, string Series) key in _rings.Keys.Where(k => k.Agent == agent).ToList())
+        {
+            _rings.TryRemove(key, out _);
+        }
+    }
+
+    private static void Prune(Ring ring, long cutoff)
+    {
+        while (ring.Buckets.Count > 0)
+        {
+            long first = ring.Buckets.Keys.First();
+            if (first >= cutoff)
+            {
+                break;
+            }
+
+            ring.Buckets.Remove(first);
+        }
+
+        // 块 ID 集合只需要覆盖热层的时间窗，限制大小即可
+        if (ring.Chunks.Count > 2000)
+        {
+            ring.Chunks.Clear();
+        }
+    }
+
+    private sealed class Ring
+    {
+        public SortedDictionary<long, byte[]> Buckets { get; } = [];
+
+        public HashSet<ChunkId> Chunks { get; } = [];
+    }
+}