feat(wallet): humanize shared wallet experience

Consolidate wallet account decoding and portfolio handling around the shared Rust IDL decoder. Simplify AMM wallet integration, remove obsolete caches and network plumbing, and cover account selection and live flows.

apps/shared/wallet/src/SequencerNetworkContext.h

@@ -0,0 +1,59 @@
+#pragma once
+
+#include <optional>
+
+#include <QString>
+#include <QtGlobal>
+
+// State shared by consumers that need to verify they are talking to a known
+// sequencer. Deployment-specific configuration belongs to the consumer; this
+// type only compares a supplied identity and tracks the probe lifecycle.
+struct SequencerNetworkSnapshot {
+    QString id;
+    QString status = QStringLiteral("config_missing");
+    QString fingerprint;
+};
+
+class SequencerNetworkContext final {
+public:
+    struct Configuration {
+        QString id;
+        QString expectedIdentity;
+        QString fingerprintPrefix;
+    };
+
+    // Replaces the active network. Returns false and publishes config_missing
+    // when the expected identity is not a 64-character lowercase hex value.
+    bool configure(Configuration configuration);
+    void clearConfiguration();
+
+    bool isConfigured() const { return m_configured; }
+    bool isReady() const { return m_snapshot.status == QStringLiteral("ready"); }
+    bool needsIdentityProbe() const;
+    const SequencerNetworkSnapshot& snapshot() const { return m_snapshot; }
+
+    // These inputs are intentionally separate: an endpoint can be configured
+    // while it is unreachable. Either loss invalidates an outstanding probe.
+    void setSequencerAvailable(bool available);
+    void setReachable(bool reachable);
+
+    // A caller must retain this generation and pass it back when its async RPC
+    // completes. Empty means a probe cannot currently start.
+    std::optional<quint64> beginIdentityProbe();
+    bool finishIdentityProbe(quint64 generation, const QString& identity);
+
+    static bool isValidIdentity(const QString& value);
+
+private:
+    void clearIdentity(const QString& status);
+    void invalidateProbe();
+
+    SequencerNetworkSnapshot m_snapshot;
+    QString m_expectedIdentity;
+    QString m_fingerprintPrefix;
+    quint64 m_probeGeneration = 0;
+    bool m_configured = false;
+    bool m_sequencerAvailable = false;
+    bool m_reachable = false;
+    bool m_probeInFlight = false;
+};