0.2.24: household-aware GP asset balances + show on Overview

Fixes a linked GP entity showing an empty Assets tab when its capital is
held under the linked account's other legal names (the eNAV often splits
one LLC across names).

- New GET /api/entities/{id}/asset-balances: household-aware, returns the
  linked account's (and its linked names') capital balances per fund, plus
  the linked account name for a clear empty state.
- Assets tab uses it; shows "linked to X but no balances on file" instead
  of a blank table when the wrong account is linked.
- GP/mgmt Overview now surfaces the total linked balance across funds with
  a "View by fund" link, so assets are visible without opening the tab.

Verified: 15/15 backend tests (incl. household case); frontend tsc + vite
build clean.

backend/tests/test_entity_link.py

@@ -1,7 +1,9 @@
 """Linking a GP entity to its investor account (so Assets can pull real balances)."""
 
+from datetime import date
+
 from tests.conftest import make_user
-from ten31portal.models import Entity, EntityType, UserRole
+from ten31portal.models import CapitalAccountStatement, Entity, EntityType, UserRole
 
 
 def test_link_entity_to_investor(auth_client, session):
@@ -29,3 +31,46 @@ def test_link_rejects_non_investor(auth_client, session):
     session.refresh(gp)
     resp = auth_client.patch(f"/api/entities/{gp.id}", json={"linked_user_id": staff.id})
     assert resp.status_code == 400
+
+
+def test_asset_balances_include_household(auth_client, session):
+    """Balances under linked (household) names of the linked account are included."""
+    primary = make_user(session, username="ten31llc", role=UserRole.investor, name="Ten31 LLC")
+    secondary = make_user(
+        session, username="ten31llc_trust", role=UserRole.investor,
+        name="Ten31 LLC Trust", primary_account_id=primary.id,
+    )
+    f1 = Entity(name="LTPF I", type=EntityType.fund)
+    f2 = Entity(name="LTPF II", type=EntityType.fund)
+    gp = Entity(name="Ten31 LLC", type=EntityType.gp, linked_user_id=primary.id)
+    session.add_all([f1, f2, gp])
+    session.commit()
+    for x in (f1, f2, gp):
+        session.refresh(x)
+
+    session.add(CapitalAccountStatement(
+        entity_id=f1.id, investor_user_id=primary.id, as_of_date=date(2026, 3, 31),
+        ending_balance_cents=600_000,
+    ))
+    # This balance sits under the linked secondary name, not the primary.
+    session.add(CapitalAccountStatement(
+        entity_id=f2.id, investor_user_id=secondary.id, as_of_date=date(2026, 3, 31),
+        ending_balance_cents=400_000,
+    ))
+    session.commit()
+
+    resp = auth_client.get(f"/api/entities/{gp.id}/asset-balances")
+    assert resp.status_code == 200, resp.text
+    body = resp.json()
+    assert body["linked_name"] == "Ten31 LLC"
+    assert {b["entity_id"] for b in body["balances"]} == {f1.id, f2.id}
+
+
+def test_asset_balances_unlinked_is_empty(auth_client, session):
+    gp = Entity(name="Mgmt", type=EntityType.mgmt_co)
+    session.add(gp)
+    session.commit()
+    session.refresh(gp)
+    resp = auth_client.get(f"/api/entities/{gp.id}/asset-balances")
+    assert resp.status_code == 200
+    assert resp.json()["balances"] == []