0.2.36: Investor View carries exit status + grey out fully-exited fund cards

The admin read-only Investor View built capital-account responses
without exited_on, so an exited position showed the active card with
$0s (the LP's own portal was correct). Extracted exit_dates() into
capital_account_router and stamp it in investor_view too; regression
test added. A fund card where every position is exited now renders
greyed (bg + title) so it reads as closed at a glance.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/tests/test_exited.py

@@ -61,6 +61,20 @@ def test_mark_exited_flows_to_partners_and_statements(auth_client, session):
     assert resp.json()["exited_on"] is None
 
 
+def test_investor_view_mirrors_exit(auth_client, session):
+    """The admin's read-only Investor View must carry exited_on exactly like the LP's own
+    portal — it was missing there (the bug behind the 'active card despite exit' report)."""
+    entity, lp = _setup_fund(session)
+    assert auth_client.put(
+        f"/api/entities/{entity.id}/partners/{lp.id}/exited",
+        json={"exited_on": "2026-05-15"},
+    ).status_code == 200
+
+    view = auth_client.get(f"/api/users/{lp.id}/investor-view").json()
+    assert view["capital_accounts"], "expected the LP's statements in the view"
+    assert all(c["exited_on"] == "2026-05-15" for c in view["capital_accounts"])
+
+
 def test_exited_member_excluded_from_rollup_committed(auth_client, session):
     entity, seller = _setup_fund(session)
     # The buyer joins the roster with the same commitment (they bought the stake).