fix: faucet health check uses JSON-RPC instead of REST

The synord RPC server is JSON-RPC only, not REST. Changed health
check from GET /health to POST with synor_getInfo method.

apps/faucet/src/main.rs

@@ -600,16 +600,45 @@ async fn faucet(
     }
 }
 
-/// Check if the RPC node is reachable.
+/// Check if the RPC node is reachable via JSON-RPC.
 async fn check_rpc_connection(state: &FaucetState) -> bool {
-    let url = format!("{}/health", state.config.rpc_url);
-    state
+    #[derive(Serialize)]
+    struct RpcRequest {
+        jsonrpc: &'static str,
+        method: &'static str,
+        params: Vec<()>,
+        id: u64,
+    }
+
+    #[derive(Deserialize)]
+    struct RpcResponse {
+        result: Option<serde_json::Value>,
+        #[allow(dead_code)]
+        error: Option<serde_json::Value>,
+    }
+
+    let request = RpcRequest {
+        jsonrpc: "2.0",
+        method: "synor_getInfo",
+        params: vec![],
+        id: 1,
+    };
+
+    let response = match state
         .http_client
-        .get(&url)
+        .post(&state.config.rpc_url)
+        .json(&request)
         .send()
         .await
-        .map(|r| r.status().is_success())
-        .unwrap_or(false)
+    {
+        Ok(r) if r.status().is_success() => r,
+        _ => return false,
+    };
+
+    match response.json::<RpcResponse>().await {
+        Ok(resp) => resp.result.is_some(),
+        Err(_) => false,
+    }
 }
 
 /// Validate Synor address format.