backend: serve single-agent task templates with their status and results, rename the kinds in storage

backend/src/MoShiro.Backend.Application/Query/QueryService.cs

@@ -138,6 +138,61 @@ public sealed class QueryService
         return Result<SeriesResult>.Ok(new SeriesResult(line, p.Range, p.Plan, bucketed.T, values, summary, gaps, events, versions));
     }
 
+    /// <summary>某个 Agent 上一个单个 Agent 任务的时序（序列 <c>target:&lt;任务 id&gt;</c>）。</summary>
+    public async ValueTask<Result<TargetSeriesResult>> TargetSeriesAsync(NodeId agent, TaskId task, RangeRequest request, MetricSelection selection, CancellationToken ct)
+    {
+        Result<(QueryRange Range, SourcePlan Plan)> planned = Plan(request, "3h");
+        if (!planned.TryGet(out (QueryRange Range, SourcePlan Plan) p, out FleetError? error))
+        {
+            return Result<TargetSeriesResult>.Fail(error);
+        }
+
+        Result<IReadOnlyList<SourceRow>> loaded = await _loader.LoadAsync(p.Plan, p.Range, agent, TargetSeries(task), ct);
+        if (!loaded.TryGet(out IReadOnlyList<SourceRow>? rows, out error))
+        {
+            return Result<TargetSeriesResult>.Fail(error);
+        }
+
+        BucketedRows bucketed = BucketedRows.Create(rows, p.Range);
+        int n = p.Range.Points;
+        var values = selection.ExportIds.ToDictionary(id => id, _ => new double?[n], StringComparer.Ordinal);
+        double widthSeconds = p.Plan.LevelWidthMs / 1000.0;
+        for (int i = 0; i < n; i++)
+        {
+            if (bucketed.Sets[i] is not { } set)
+            {
+                continue;
+            }
+
+            Dictionary<string, double> exported = ExportEvaluator.Evaluate(set, selection.ExportIds, bucketed.RowCounts[i] * widthSeconds);
+            foreach (string id in selection.ExportIds)
+            {
+                if (exported.TryGetValue(id, out double v))
+                {
+                    values[id][i] = v;
+                }
+            }
+        }
+
+        var versions = new Dictionary<string, string>(StringComparer.Ordinal);
+        foreach (string id in selection.ExportIds)
+        {
+            if (MetricRegistry.TryFindExport(id, out MetricDef def, out _))
+            {
+                versions[id] = def.Fingerprint;
+            }
+        }
+
+        SummaryResult summary = Summarize(bucketed.Merge(), bucketed.TotalRows, p.Plan, p.Range, selection, new Dictionary<string, double>());
+        return Result<TargetSeriesResult>.Ok(new TargetSeriesResult(p.Range, p.Plan, bucketed.T, values, summary, versions));
+    }
+
+    /// <summary>这个单个 Agent 任务最后一个样本的时刻（Unix 毫秒）；还没有数据返回 null。</summary>
+    public ValueTask<long?> TargetLatestAsync(NodeId agent, TaskId task, CancellationToken ct) =>
+        _loader.LatestSampleMsAsync(agent, TargetSeries(task), _time.GetUtcNow().ToUnixTimeMilliseconds(), ct);
+
+    private static string TargetSeries(TaskId task) => "target:" + task.Value;
+
     /// <summary>这条线路最早的数据（Unix 毫秒）；没有数据返回 null。</summary>
     public ValueTask<long?> EarliestAsync(LineKey line, CancellationToken ct) =>
         _loader.EarliestSampleMsAsync(line.Listener, line.Series, _time.GetUtcNow().ToUnixTimeMilliseconds(), ct);