fix(settings): scope portfolio groups by wallet identity

Market-tab portfolio groups were tied to a wallet by a hash of its
address set. That hash changed whenever an address was added, so a
group built for a wallet could silently drop out of view once the
wallet gained a new address.

- Groups are now scoped by the wallet's stable id, which is persisted
  and never derived from the address set, so adding an address can no
  longer orphan a group.
- An older build's address-hash scope fails open (the group stays
  visible) and is migrated once per wallet per session to the stable id.
  A legacy group is claimed when its old hash matches, when one of its
  own addresses belongs to this wallet, or when only one wallet is
  known; anything ambiguous is left legacy and stays visible.
- Scope filtering waits until the wallet's addresses are loaded, so a
  group never flashes an empty 0.0000 balance and Add stays disabled
  until the wallet is resolved. This works on Lite, which never stamps
  an address-update time.

Behaviour: an older build opened after this change hides groups tagged
with a stable "w:" scope (they are not deleted and return on the next
upgrade) - worth a release note.

Tests: group visibility across global, stable and legacy scopes with the
wallet resolved and not; the migration rules (hash match, address
overlap, single-wallet claim, ambiguous left alone, idempotent); and a
save/load round trip where an address-set change cannot orphan the scope.

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

src/app.cpp

@@ -1085,6 +1085,9 @@ void App::update()
         state_.rebuildAddressList();
     }
 
+    // Move legacy (address-hash) portfolio scopes to the stable wallet id once this wallet's addresses are in.
+    reattachLegacyPortfolioScopes();
+
     using RefreshTimer = services::NetworkRefreshService::Timer;
 
     // Wipe a secret (seed/private key) from the clipboard once its auto-clear delay elapses.