fix(worker): clean up orphaned worktree when the DB row insert fails

If WorktreeAddAsync succeeds but the worktrees-row insert throws, the
worktree was left on disk and branch undeleted with nothing tracking it.
Wrap the insert in try/catch and best-effort remove the worktree+branch
(non-cancellable) before rethrowing.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/ClaudeDo.Worker/Runner/WorktreeManager.cs

@@ -92,21 +92,37 @@ public sealed class WorktreeManager
         }
 
         // Insert worktrees row AFTER git succeeds — if git throws, no row is created.
-        using var context = _dbFactory.CreateDbContext();
-        var wtRepo = new WorktreeRepository(context);
-        // Drop any stale row from a prior run (force-remove may have left the DB side behind).
-        await wtRepo.DeleteAsync(task.Id, ct);
-        await wtRepo.AddAsync(new WorktreeEntity
+        // If the insert itself fails, the worktree is already on disk with nothing
+        // tracking it: remove it (best-effort, non-cancellable) before rethrowing.
+        try
         {
-            TaskId = task.Id,
-            Path = worktreePath,
-            BranchName = branchName,
-            BaseCommit = baseCommit,
-            HeadCommit = null,
-            DiffStat = null,
-            State = WorktreeState.Active,
-            CreatedAt = DateTime.UtcNow,
-        }, ct);
+            using var context = _dbFactory.CreateDbContext();
+            var wtRepo = new WorktreeRepository(context);
+            // Drop any stale row from a prior run (force-remove may have left the DB side behind).
+            await wtRepo.DeleteAsync(task.Id, ct);
+            await wtRepo.AddAsync(new WorktreeEntity
+            {
+                TaskId = task.Id,
+                Path = worktreePath,
+                BranchName = branchName,
+                BaseCommit = baseCommit,
+                HeadCommit = null,
+                DiffStat = null,
+                State = WorktreeState.Active,
+                CreatedAt = DateTime.UtcNow,
+            }, ct);
+        }
+        catch (Exception dbEx)
+        {
+            _logger.LogError(dbEx,
+                "Failed to record worktree row for task {TaskId}; removing orphaned worktree at {Path}",
+                task.Id, worktreePath);
+            try { await _git.WorktreeRemoveAsync(workingDir, worktreePath, force: true, CancellationToken.None); }
+            catch (Exception rmEx) { _logger.LogWarning(rmEx, "Failed to remove orphaned worktree at {Path}", worktreePath); }
+            try { await _git.BranchDeleteAsync(workingDir, branchName, force: true, CancellationToken.None); }
+            catch (Exception delEx) { _logger.LogWarning(delEx, "Failed to delete orphaned branch {Branch}", branchName); }
+            throw;
+        }
 
         _logger.LogInformation("Created worktree for task {TaskId} at {Path} (branch {Branch}, base {Base})",
             task.Id, worktreePath, branchName, baseCommit);