Surface the delegation tree in the knob panel (GUI parity)

CHANGELOG.md

@@ -24,6 +24,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   TangleBrain-enforced guarantee, so a delegate that loses the env degrades safely to `unlinked` (never
   an error). This was the deferred half of the scatter-gather epic whose entry criterion was a
   live-verification spike — now done.
+- **Knob panel surfaces the delegation tree.** The panel's "Delegated sub-tasks" card now shows a
+  **Linked to** stat (`N parent task(s)`, with any `unlinked` sub-calls noted) — GUI parity with the
+  `tanglebrain --stats` rollup, so the per-parent-task linkage is visible in the panel, not just the
+  CLI. Read-only; no new endpoint (the data already rides `view_stats`'s rollup payload).
 
 ### Fixed
 

tanglebrain/gui/static/index.html

@@ -119,10 +119,18 @@ <h2>Pricing reference</h2>
     const dg = s.delegates || {};
     if (dg.count) {
       const backends = Object.entries(dg.by_backend || {}).map(([k, v]) => `${esc(k)} ${v.count || 0}`).join(", ") || "—";
+      // Parent-task tree: how many top-level tasks the sub-calls link back to. Mirrors the CLI's
+      // "Linked to: N parent task(s)" line; sub-calls run outside a propagated task are "unlinked".
+      const byParent = dg.by_parent || {};
+      const linked = Object.keys(byParent).filter((k) => k !== "unlinked").length;
+      const unlinked = (byParent.unlinked || {}).count || 0;
+      let tree = linked ? `${linked} parent task(s)` : `${unlinked} unlinked`;
+      if (linked && unlinked) tree += `, ${unlinked} unlinked`;
       html += `<h3 style="margin:1rem 0 .4rem">Delegated sub-tasks <span class="muted">(offloaded by orchestrators)</span></h3>
       <div class="stat-grid">
         <div class="stat"><div class="label">Sub-tasks</div><div class="value">${dg.count}</div></div>
         <div class="stat"><div class="label">By backend</div><div class="value mono" style="font-size:.95rem">${backends}</div></div>
+        <div class="stat"><div class="label">Linked to</div><div class="value mono" style="font-size:.95rem">${esc(tree)}</div></div>
         <div class="stat"><div class="label">Est. tokens (in / out)</div><div class="value mono" style="font-size:.95rem">${(dg.in_tokens_est||0).toLocaleString()} / ${(dg.out_tokens_est||0).toLocaleString()}</div></div>
         <div class="stat"><div class="label">Cloud-equiv</div><div class="value mono" style="font-size:.95rem">${money(dg.cloud_equiv_usd)}</div></div>
       </div>

tests/test_gui.py

@@ -124,6 +124,19 @@ def test_includes_delegate_breakdown(self):
         self.assertEqual(delegates["count"], 1)
         self.assertEqual(delegates["by_backend"]["local-x"]["count"], 1)
 
+    def test_includes_parent_task_tree(self):
+        # The panel's delegate card renders the by_parent tree, so view_stats must carry it through.
+        recs = [
+            {"kind": "delegate", "model": "local-x", "parent_task_id": "p1"},
+            {"kind": "delegate", "model": "local-x", "parent_task_id": "p2"},
+            {"kind": "delegate", "model": "local-x"},
+        ]
+        with patch("tanglebrain.gui.views.read_records", return_value=recs):
+            out = views.view_stats()
+        by_parent = out["summary"]["delegates"]["by_parent"]
+        self.assertEqual({k for k in by_parent if k != "unlinked"}, {"p1", "p2"})
+        self.assertEqual(by_parent["unlinked"]["count"], 1)
+
 
 class RunPromptTest(unittest.TestCase):
     def test_happy_path_reports_served(self):