feat(worktrees): add GetOverviewAsync for overview modal

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ClaudeDo.Worker/Worktrees/WorktreeMaintenanceService.cs

@@ -71,6 +71,30 @@ public sealed class WorktreeMaintenanceService
         return new ResetResult(removed, rows.Count, Blocked: false, RunningTasks: 0);
     }
 
+    public async Task<IReadOnlyList<WorktreeOverviewRow>> GetOverviewAsync(
+        string? listId, CancellationToken ct = default)
+    {
+        using var context = _dbFactory.CreateDbContext();
+        var query = from w in context.Worktrees
+                    join t in context.Tasks on w.TaskId equals t.Id
+                    join l in context.Lists on t.ListId equals l.Id
+                    select new
+                    {
+                        w.TaskId, t.Title, t.Status, ListId = l.Id, ListName = l.Name,
+                        w.Path, w.BranchName, w.State, w.DiffStat, w.CreatedAt,
+                    };
+
+        if (!string.IsNullOrEmpty(listId))
+            query = query.Where(x => x.ListId == listId);
+
+        var rows = await query.AsNoTracking().ToListAsync(ct);
+
+        return rows.Select(x => new WorktreeOverviewRow(
+            x.TaskId, x.Title, x.Status, x.ListId, x.ListName,
+            x.Path, x.BranchName, x.State, x.DiffStat, x.CreatedAt,
+            PathExistsOnDisk: !string.IsNullOrWhiteSpace(x.Path) && Directory.Exists(x.Path))).ToList();
+    }
+
     private async Task<bool> TryRemoveAsync(WorktreeRow row, bool force, CancellationToken ct)
     {
         var repoDirExists = !string.IsNullOrWhiteSpace(row.WorkingDir) && Directory.Exists(row.WorkingDir);

src/ClaudeDo.Worker/Worktrees/WorktreeOverviewRow.cs

@@ -0,0 +1,17 @@
+using ClaudeDo.Data.Models;
+using TaskStatus = ClaudeDo.Data.Models.TaskStatus;
+
+namespace ClaudeDo.Worker.Worktrees;
+
+public sealed record WorktreeOverviewRow(
+    string TaskId,
+    string TaskTitle,
+    TaskStatus TaskStatus,
+    string ListId,
+    string ListName,
+    string Path,
+    string BranchName,
+    WorktreeState State,
+    string? DiffStat,
+    DateTime CreatedAt,
+    bool PathExistsOnDisk);