feat: HealthCheckable interface on DaemonRpc and WalletRpc

Services implement healthCheck() returning {status, detail, stale?}.
Status page refactored to use healthCheck() instead of ad-hoc checks.
Statuses: healthy, degraded (stale data), unhealthy (unreachable).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/Mod/Chain/Contracts/HealthCheckable.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Mod\Chain\Contracts;
+
+/**
+ * Service health check interface.
+ *
+ *   $result = $service->healthCheck();
+ *   if ($result['status'] === 'healthy') { ... }
+ */
+interface HealthCheckable
+{
+    /**
+     * @return array{status: string, detail: string, stale?: bool}
+     */
+    public function healthCheck(): array;
+}

app/Mod/Chain/Services/DaemonRpc.php

@@ -14,7 +14,7 @@ use Illuminate\Support\Facades\Http;
  *   $info = $rpc->getInfo();
  *   $block = $rpc->getBlockByHeight(12345);
  */
-class DaemonRpc implements \Mod\Chain\Contracts\ChainDaemon
+class DaemonRpc implements \Mod\Chain\Contracts\ChainDaemon, \Mod\Chain\Contracts\HealthCheckable
 {
     private string $endpoint;
     private int $cacheTtl;
@@ -154,4 +154,26 @@ class DaemonRpc implements \Mod\Chain\Contracts\ChainDaemon
             return ['error' => 'Daemon unreachable', '_offline' => true];
         }
     }
+
+    public function healthCheck(): array
+    {
+        $info = $this->getInfo();
+
+        if (isset($info['_offline'])) {
+            return ['status' => 'unhealthy', 'detail' => 'Unreachable'];
+        }
+
+        if (isset($info['_stale'])) {
+            return [
+                'status' => 'degraded',
+                'detail' => 'Stale data — height ' . number_format($info['height'] ?? 0),
+                'stale' => true,
+            ];
+        }
+
+        return [
+            'status' => 'healthy',
+            'detail' => 'Height ' . number_format($info['height'] ?? 0) . ' — ' . ($info['status'] ?? 'OK'),
+        ];
+    }
 }

app/Mod/Chain/Services/WalletRpc.php

@@ -10,7 +10,7 @@ use Illuminate\Support\Facades\Http;
  *   $wallet = app(WalletRpc::class);
  *   $wallet->registerAlias('myname', $address, 'v=lthn1;type=user');
  */
-class WalletRpc implements \Mod\Chain\Contracts\ChainWallet
+class WalletRpc implements \Mod\Chain\Contracts\ChainWallet, \Mod\Chain\Contracts\HealthCheckable
 {
     private string $endpoint;
 
@@ -99,4 +99,19 @@ class WalletRpc implements \Mod\Chain\Contracts\ChainWallet
 
         return $data['result'] ?? $data['error'] ?? [];
     }
+
+    public function healthCheck(): array
+    {
+        try {
+            $balance = $this->getBalance();
+
+            if (isset($balance['error'])) {
+                return ['status' => 'unhealthy', 'detail' => 'Unreachable'];
+            }
+
+            return ['status' => 'healthy', 'detail' => 'Connected'];
+        } catch (\Throwable $e) {
+            return ['status' => 'unhealthy', 'detail' => 'Unreachable'];
+        }
+    }
 }

app/Website/Lethean/Controllers/HomeController.php

@@ -159,29 +159,22 @@ class HomeController extends Controller
     public function status(): \Illuminate\View\View
     {
         $chainInfo = $this->rpc->getInfo();
-        try {
-            $walletInfo = $this->wallet->getBalance();
-        } catch (\Throwable $e) {
-            $walletInfo = ['error' => 'Wallet unreachable'];
-        }
+        $chainHealth = $this->rpc->healthCheck();
+        $walletHealth = $this->wallet->healthCheck();
         $liveGateways = $this->registry->liveGateways();
         $pendingClaims = \Mod\Names\Models\NameClaim::pending()->count();
 
         $checks = [
             'chain' => [
                 'label' => 'Blockchain Daemon',
-                'ok' => ! isset($chainInfo['_offline']),
-                'stale' => isset($chainInfo['_stale']),
-                'detail' => isset($chainInfo['_offline'])
-                    ? 'Unreachable'
-                    : 'Height ' . number_format($chainInfo['height'] ?? 0) . ' — ' . ($chainInfo['status'] ?? 'unknown'),
+                'ok' => $chainHealth['status'] !== 'unhealthy',
+                'stale' => $chainHealth['stale'] ?? false,
+                'detail' => $chainHealth['detail'],
             ],
             'wallet' => [
                 'label' => 'Registry Wallet',
-                'ok' => ! isset($walletInfo['error']),
-                'detail' => isset($walletInfo['error'])
-                    ? 'Unreachable'
-                    : 'Connected',
+                'ok' => $walletHealth['status'] === 'healthy',
+                'detail' => $walletHealth['detail'],
             ],
             'gateways' => [
                 'label' => 'Paired Gateways',