fix(worker): record real raw token usage per run, not the uncached remainder

task_runs.tokens_in only ever held the API's uncached "input_tokens" field
(off by a factor of ~400,000 on a resumed session), and tokens_out summed
only the last result event instead of the whole session. TaskRunner now
reads each run's cache-read/cache-write/input/output totals from the
session transcript via a new ITranscriptUsageReader.ReadSessionTotalsAsync,
storing the delta against prior runs on the same session so a --resume
doesn't double-count. New task_runs.cache_read_tokens/cache_write_tokens
columns; the Session tab now shows the raw total (what actually counts
against the 5h/7d usage limit) with a breakdown tooltip.

src/ClaudeDo.Worker/Usage/TranscriptUsageReader.cs

@@ -62,6 +62,33 @@ public sealed class TranscriptUsageReader : ITranscriptUsageReader
         return Task.FromResult<IReadOnlyList<UsageAggregateRow>>(rows);
     }
 
+    public Task<SessionUsageTotals?> ReadSessionTotalsAsync(string sessionId, CancellationToken ct = default)
+    {
+        if (string.IsNullOrWhiteSpace(sessionId) || !Directory.Exists(_projectsRoot))
+            return Task.FromResult<SessionUsageTotals?>(null);
+
+        var file = Directory
+            .EnumerateFiles(_projectsRoot, $"{sessionId}.jsonl", SearchOption.AllDirectories)
+            .FirstOrDefault();
+        if (file is null) return Task.FromResult<SessionUsageTotals?>(null);
+
+        var seenKeys = new HashSet<string>();
+        long input = 0, output = 0, cacheRead = 0, cacheCreation = 0;
+        foreach (var record in GetOrReadFile(file))
+        {
+            ct.ThrowIfCancellationRequested();
+            if (!seenKeys.Add(record.DedupeKey)) continue;
+
+            input += record.InputTokens;
+            output += record.OutputTokens;
+            cacheRead += record.CacheReadTokens;
+            cacheCreation += record.CacheCreationTokens;
+        }
+
+        return Task.FromResult<SessionUsageTotals?>(
+            new SessionUsageTotals(input, output, cacheRead, cacheCreation));
+    }
+
     private List<UsageMessageRecord> GetOrReadFile(string file)
     {
         var info = new FileInfo(file);
@@ -100,6 +127,7 @@ public sealed class TranscriptUsageReader : ITranscriptUsageReader
 
                 var date = DateOnly.FromDateTime(ts.LocalDateTime);
                 var model = modelEl.GetString()!;
+                if (model == "<synthetic>") continue;
 
                 long input = 0, output = 0, cacheRead = 0, cacheCreation = 0;
                 if (msg.TryGetProperty("usage", out var usage) && usage.ValueKind == JsonValueKind.Object)