fix(review): address MEDIUM items from final code-reviewer

- anti_unifier: remove arbitrary root fallback when no agent_node_id (only apply root-form when nid known; primary pipeline path unaffected)
- depth_canonical: filter build_node_depths to he/grc (or nodes with root) so English nodes no longer pollute node_depths with language-only entries

Tests re-run green. Matches review recommendations for the 3-lang depth feature.

recognition/anti_unifier.py

@@ -272,18 +272,12 @@ def recognize(
             value, evidence = _lift_slot(slot, original_tokens, span)
             feature_evidence[slot.feature_name] = (value, evidence)
 
-        # 3-lang root form for agent in proposition when depth (nid-keyed via agent_node_id if given; proof of canonical match).
-        # Uses canonicalize_token for consistency with derive path; no mutation.
-        if depths and 'agent' in feature_evidence:
+        # 3-lang root form for agent in proposition when depth (nid-keyed via agent_node_id).
+        # Only applied when explicit nid is provided (primary pipeline path always does).
+        # Without nid we do not guess a root (avoids unrelated root in proposition).
+        if depths and 'agent' in feature_evidence and agent_node_id and agent_node_id in depths:
             val, ev = feature_evidence['agent']
-            nid = agent_node_id
-            if nid and nid in depths:
-                val = canonicalize_token(str(val), nid, depths)
-            else:
-                for d in depths.values():
-                    if d.get('language') in ('he', 'grc') and d.get('root'):
-                        val = d['root']
-                        break
+            val = canonicalize_token(str(val), agent_node_id, depths)
             feature_evidence['agent'] = (val, ev)
 
         proposition = FeatureBundle.from_mapping(feature_evidence)

recognition/depth_canonical.py

@@ -86,7 +86,7 @@ def build_node_depths(nodes: Sequence[Any]) -> dict[str, dict]:
             }.items() if v is not None
         }
         for n in nodes
-        if getattr(n, "language", None) or getattr(n, "root", None)
+        if getattr(n, "language", None) in ("he", "grc") or getattr(n, "root", None)
     }