feat(lite): M2b-1/2 — shared-bridge refactor + sync/refresh into WalletState

Shared-bridge refactor (litelib is a global singleton; every LiteClientBridge calls
litelib_shutdown() on destruction, so services must not each own one):
- LiteWalletLifecycleService, LiteWalletGateway, LiteSyncService now take a non-owning
  LiteClientBridge*; LiteWalletController owns the single bridge and passes &bridge_.

Sync + controller refresh:
- LiteSyncService::startSync executes the real "sync" command (was a stub).
- LiteWalletController: startSync() (auto-fires when a wallet becomes ready) and
  refreshWalletState(WalletState&) — polls syncstatus, runs gateway.refresh(), maps the
  bundle, applies balances/addresses/transactions/sync into WalletState.

Tests:
- fake_lite_backend.h returns command-shaped JSON (per tests/fixtures/lite/result_parsers.json).
- testLiteWalletControllerRefreshPopulatesState drives the full path against the fake.
- Surfaced + worked around a real integration issue: parseLiteInfoResponse requires
  latest_block_height and the gateway aborts the whole refresh on the first command's
  parse failure (fragile vs partial backend responses; hardening tracked for M2b-3).

Verified: ctest green; lite+backend, full-node, lite-no-backend apps + lite_smoke build clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/wallet/lite_sync_service.cpp

@@ -166,11 +166,11 @@ LiteSyncRecoveryDecision evaluateLiteSyncRecovery(const LiteSyncRecoveryInput& i
 
 LiteSyncService::LiteSyncService(WalletCapabilities capabilities,
                                  LiteConnectionSettings connectionSettings,
-                                 LiteClientBridge bridge,
+                                 LiteClientBridge* bridge,
                                  LiteSyncServiceOptions options)
     : capabilities_(capabilities),
       connectionSettings_(std::move(connectionSettings)),
-      bridge_(std::move(bridge)),
+      bridge_(bridge),
       options_(options)
 {
 }
@@ -179,7 +179,7 @@ LiteSyncAvailability LiteSyncService::availability() const
 {
     if (!isLiteBuild(capabilities_)) return LiteSyncAvailability::UnsupportedBuild;
     if (!supportsLiteBackend(capabilities_)) return LiteSyncAvailability::BackendUnavailable;
-    if (!bridge_.available()) return LiteSyncAvailability::BridgeUnavailable;
+    if (!bridge_ || !bridge_->available()) return LiteSyncAvailability::BridgeUnavailable;
     if (!selectLiteServer(connectionSettings_).ok) return LiteSyncAvailability::NoUsableServer;
     if (!options_.allowSyncStatusBridgeCalls) return LiteSyncAvailability::BridgeCallsDisabled;
     return LiteSyncAvailability::Ready;
@@ -199,7 +199,7 @@ LiteSyncPlan LiteSyncService::planStartSync(const LiteSyncStartRequest& request)
     return makePlan(
         LiteSyncOperation::StartSync,
         request.serverUrl,
-        false,
+        options_.allowSyncStatusBridgeCalls,
         request.mode,
         request.forceRescan,
         request.afterRestore);
@@ -229,9 +229,21 @@ LiteSyncStartResult LiteSyncService::startSync(const LiteSyncStartRequest& reque
         return blockedStartResult(plan, status());
     }
 
-    return blockedStartResult(
-        plan,
-        makeSyncScaffoldStatus(WalletBackendState::Unavailable, "lite sync start execution is not implemented"));
+    LiteSyncStartResult result;
+    result.plan = plan;
+    result.attempted = true;
+
+    const auto bridgeCall = bridge_->execute(plan.command, plan.args);
+    if (!bridgeCall.ok) {
+        result.status = makeSyncScaffoldStatus(WalletBackendState::Error, "lite sync start bridge call failed");
+        result.error = result.status.message;
+        return result;
+    }
+
+    result.ok = true;
+    result.syncStarted = true;
+    result.status = makeSyncScaffoldStatus(WalletBackendState::Syncing, "lite sync started");
+    return result;
 }
 
 LiteSyncStatusResult LiteSyncService::pollSyncStatus(const LiteSyncStatusRequest& request)
@@ -245,7 +257,7 @@ LiteSyncStatusResult LiteSyncService::pollSyncStatus(const LiteSyncStatusRequest
     result.plan = plan;
     result.attempted = true;
 
-    const auto bridgeCall = bridge_.execute(plan.command, plan.args);
+    const auto bridgeCall = bridge_->execute(plan.command, plan.args);
     result.bridgeResponseRedacted = bridgeCall.ok || !bridgeCall.error.empty() ? "<redacted>" : "<empty>";
     if (!bridgeCall.ok) {
         result.status = makeSyncScaffoldStatus(WalletBackendState::Error, "lite syncstatus bridge call failed");
@@ -334,7 +346,7 @@ WalletBackendStatus LiteSyncService::statusFor(LiteSyncAvailability availability
         case LiteSyncAvailability::BridgeUnavailable:
             return makeSyncScaffoldStatus(
                 WalletBackendState::Unavailable,
-                detail.empty() ? bridge_.unavailableReason() : detail);
+                detail.empty() ? (bridge_ ? bridge_->unavailableReason() : "lite bridge is unavailable") : detail);
         case LiteSyncAvailability::BridgeCallsDisabled:
             return makeSyncScaffoldStatus(
                 WalletBackendState::Unavailable,