fix(planning): return to the list base branch after integration cleanup, not a guessed task branch

src/ClaudeDo.Worker/Planning/PlanningAggregator.cs

@@ -133,15 +133,29 @@ public sealed class PlanningAggregator
         var current = await _git.GetCurrentBranchAsync(repoDir, ct);
         if (string.Equals(current, branch, StringComparison.Ordinal))
         {
-            var branches = await _git.ListLocalBranchesAsync(repoDir, ct);
-            var target = branches.FirstOrDefault(b => b != branch && !b.StartsWith("claudedo/", StringComparison.Ordinal)) ?? "main";
-            await _git.CheckoutBranchAsync(repoDir, target, ct);
+            await _git.CheckoutBranchAsync(repoDir, await ResolveReturnBranchAsync(planning, repoDir, ct), ct);
         }
 
         try { await _git.BranchDeleteAsync(repoDir, branch, force: true, ct); }
         catch { /* already gone — idempotent */ }
     }
 
+    /// <summary>
+    /// Rücksprung vom Integration-Branch: <c>list_config.base_branch</c>, sonst <c>main</c> (bzw. <c>master</c>).
+    /// Nie aus der Branchliste raten — die enthält auch Task-Branches, die in Worktrees ausgecheckt sind.
+    /// </summary>
+    private async Task<string> ResolveReturnBranchAsync(TaskEntity planning, string repoDir, CancellationToken ct)
+    {
+        using var ctx = _dbFactory.CreateDbContext();
+        var baseBranch = await ctx.ListConfigs.AsNoTracking()
+            .Where(c => c.ListId == planning.ListId)
+            .Select(c => c.BaseBranch)
+            .FirstOrDefaultAsync(ct);
+        if (!string.IsNullOrWhiteSpace(baseBranch)) return baseBranch;
+        var branches = await _git.ListLocalBranchesAsync(repoDir, ct);
+        return !branches.Contains("main") && branches.Contains("master") ? "master" : "main";
+    }
+
     private async Task<(TaskEntity planning, string repoDir, IReadOnlyList<TaskEntity> children)>
         LoadPlanningContextAsync(string planningTaskId, CancellationToken ct)
     {