Fix SignerPicker not showing in SmartWalletsDemo

[tomas-martins-crossmint]

SignerPicker was invisible even when the wallet had selectable signers. The picker used a .task attached to a Group/Section that starts empty, and SwiftUI doesn't fire .task on an empty section — so by the time wallet.signers() returned, the layout had already settled and the section never appeared.

Changes

• AppState now owns delegatedSigners and exposes a loadSigners() method that calls wallet?.signers(). It's called after fetchBalance() in both loadWallet and switchChain (for cached wallets), so signers are always populated before any view renders.
• loadSigners() also restores the auto-selection behavior from the old .task: if no signer is currently selected, it picks the first selectable locator and calls selectSigner.
• SignerPicker drops the local @State var delegatedSigners and the .task entirely, reading from appState.delegatedSigners instead. Picker now shows whenever there's at least one selectable signer (was count > 1). Locator fallback fixed to signer.locator ?? signer.signer since the API can return the locator in either field.
• SignersView.loadSigners() delegates to appState.loadSigners() and reads from appState.delegatedSigners to stay in sync.

[greptile-apps]

Prompt To Fix All With AI

Fix the following 2 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 2
Examples/SmartWalletsDemo/SmartWalletsDemo/Playground/AppState.swift:95-110
**`createWallet` skips `loadSigners()`, leaving the signer unselected**

After wallet creation, `loadSigners()` is never called, so `delegatedSigners` stays `[]` and `selectSigner` is never invoked. The `SignerPicker` binding falls back to `opts.first?.id` visually (the recovery locator), but `wallet.useSigner(config)` is never called on the underlying SDK — meaning wallet operations after creation may run without an explicitly configured signer. Both `loadWallet` and `switchChain` call `await loadSigners()` after `fetchBalance()`, but `createWallet` does not, creating an inconsistent state.

### Issue 2 of 2
Examples/SmartWalletsDemo/SmartWalletsDemo/Playground/Signers/SignersView.swift:34-44
**Inconsistency between `SignerPicker` and `SignersView` for signers where `locator` is nil**

`SignerPicker` now uses `signer.locator ?? signer.signer` so a signer where only the `signer` field is populated will appear as a selectable option in the picker. However, `SignersView` still uses `id: \.locator` for `ForEach` and guards `if let locator = signer.locator` — meaning that same signer won't be rendered in the Signers management screen and can't be removed. If the API does return entries with `locator == nil`, those signers end up in an inconsistent state: selectable but not removable.

_{Reviews (1): Last reviewed commit: "Fix SignerPicker not showing in SmartWal..." | Re-trigger Greptile}

[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
Examples/SmartWalletsDemo/SmartWalletsDemo/Playground/Signers/SignersView.swift:14-26
The `signerItems` computed property is sandwiched between `@State` property declarations (`isLoadingSigners` above and `alertTitle`/`alertMessage`/`showAlert` below), making the property group harder to scan. Consider grouping all stored `@State` properties together and placing computed properties in a separate section.

```suggestion
    @State private var isLoadingSigners = false
    @State private var alertTitle = ""
    @State private var alertMessage = ""
    @State private var showAlert = false

    private var isRemovingSigner: Bool { removingSignerLocator != nil }

    private var signerItems: [(locator: String, model: WalletDelegatedSignerConfigApiModel)] {
        appState.delegatedSigners.compactMap { signer in
            guard let locator = signer.locator ?? signer.signer else { return nil }
            return (locator: locator, model: signer)
        }
    }
```

_{Reviews (2): Last reviewed commit: "Address signer state gaps after wallet c..." | Re-trigger Greptile}

[greptile-apps]

_{Reviews (3): Last reviewed commit: "Group @State properties before computed ..." | Re-trigger Greptile}