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/ui/windows/balance_components.cpp

@@ -724,12 +724,12 @@ void RenderSharedAddressList(App* app, float listH, float availW,
                 ImGui::Separator();
                 if (ImGui::BeginMenu(TR("portfolio_add_to"))) {
                     const auto& pf = app->settings()->getPortfolioEntries();
-                    const std::string activeHash = app->activeWalletIdentityHash();
+                    const std::string scopeId = app->portfolioScopeId();
                     int shown = 0;
                     for (int pi = 0; pi < (int)pf.size(); pi++) {
-                        // Only this wallet's groups (or legacy/unscoped), matching the Market summary —
-                        // don't offer to add this address to another wallet's group.
-                        if (!(pf[pi].scope.empty() || activeHash.empty() || pf[pi].scope == activeHash))
+                        // Only this wallet's groups (or global / not-yet-migrated legacy), matching the Market
+                        // summary - don't offer to add this address to another wallet's group.
+                        if (!pf[pi].visibleInWallet(scopeId))
                             continue;
                         // PushID keeps the item ID unique even when two groups share a label (a
                         // label-derived MenuItem ID would collide); a blank label shows a placeholder