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.

tests/ClaudeDo.Data.Tests/UsageGateAndRunModelTests.cs

@@ -117,4 +117,58 @@ public sealed class UsageGateAndRunModelTests : IDisposable
 
         Assert.Null(reloaded.Model);
     }
+
+    [Fact]
+    public async Task TaskRun_cache_token_fields_roundtrip_when_set()
+    {
+        var list = new ListEntity { Id = "l3", Name = "Test", CreatedAt = DateTime.UtcNow };
+        var task = new TaskEntity { Id = "t3", ListId = "l3", Title = "T", Status = TaskStatus.Idle, CreatedAt = DateTime.UtcNow };
+        var run = new TaskRunEntity
+        {
+            Id = "r3",
+            TaskId = "t3",
+            RunNumber = 1,
+            IsRetry = false,
+            Prompt = "do the thing",
+            CacheReadTokens = 12345,
+            CacheWriteTokens = 678,
+        };
+        _ctx.Lists.Add(list);
+        _ctx.Tasks.Add(task);
+        _ctx.TaskRuns.Add(run);
+        await _ctx.SaveChangesAsync();
+
+        await using var freshCtx = new ClaudeDoDbContext(
+            new DbContextOptionsBuilder<ClaudeDoDbContext>().UseSqlite($"Data Source={_dbPath}").Options);
+        var reloaded = await freshCtx.TaskRuns.AsNoTracking().FirstAsync(r => r.Id == "r3");
+
+        Assert.Equal(12345, reloaded.CacheReadTokens);
+        Assert.Equal(678, reloaded.CacheWriteTokens);
+    }
+
+    [Fact]
+    public async Task TaskRun_cache_token_fields_stay_null_when_not_set()
+    {
+        var list = new ListEntity { Id = "l4", Name = "Test", CreatedAt = DateTime.UtcNow };
+        var task = new TaskEntity { Id = "t4", ListId = "l4", Title = "T", Status = TaskStatus.Idle, CreatedAt = DateTime.UtcNow };
+        var run = new TaskRunEntity
+        {
+            Id = "r4",
+            TaskId = "t4",
+            RunNumber = 1,
+            IsRetry = false,
+            Prompt = "do the thing",
+        };
+        _ctx.Lists.Add(list);
+        _ctx.Tasks.Add(task);
+        _ctx.TaskRuns.Add(run);
+        await _ctx.SaveChangesAsync();
+
+        await using var freshCtx = new ClaudeDoDbContext(
+            new DbContextOptionsBuilder<ClaudeDoDbContext>().UseSqlite($"Data Source={_dbPath}").Options);
+        var reloaded = await freshCtx.TaskRuns.AsNoTracking().FirstAsync(r => r.Id == "r4");
+
+        Assert.Null(reloaded.CacheReadTokens);
+        Assert.Null(reloaded.CacheWriteTokens);
+    }
 }