fix(apps/amm): repair addCustomToken — restore token resolution and closing brace

The Copilot Autofix squash reworked addCustomToken to persist the canonical
definitionId (and to fail when the store write fails), but it deleted the line
that resolves the token — `const QVariantList rows = resolveTokens(probe, …)` —
while still calling `rows.first()`, and it dropped the function's closing brace.
The result didn't compile: `rows` was undefined and customTokenStorePath parsed
as a nested definition ("function definition is not allowed here").

Restore the resolveTokens call and the `rows.isEmpty()` guard before `rows` is
used, and re-add the closing brace. The autofix's intent is preserved: resolve
the pasted id, keep the canonical definitionId, persist it, and surface a
backend_error if saveCustomTokenIds fails

apps/amm/src/AmmUiBackend.cpp

@@ -364,6 +364,11 @@ QVariantMap AmmUiBackend::addCustomToken(QString tokenId)
     // real fungible token (a non-fungible / unreadable id yields no row).
     QVariantMap probe;
     probe.insert(QStringLiteral("tokenIds"), QVariantList{id});
+    const QVariantList rows = m_logos->amm_module.resolveTokens(probe, isWalletOpen());
+    if (rows.isEmpty())
+        return QVariantMap{{QStringLiteral("ok"), false},
+                           {QStringLiteral("error"), QStringLiteral("unresolved")}};
+
     const QVariantMap token = rows.first().toMap();
     const QString canonicalId = token.value(QStringLiteral("definitionId")).toString();
     if (canonicalId.isEmpty())
@@ -378,6 +383,7 @@ QVariantMap AmmUiBackend::addCustomToken(QString tokenId)
                                {QStringLiteral("error"), QStringLiteral("backend_error")}};
     }
     return QVariantMap{{QStringLiteral("ok"), true}, {QStringLiteral("token"), token}};
+}
 
 QString AmmUiBackend::customTokenStorePath() const
 {