Fix sudo nginx and psql commands to use full paths

- Change nginx command from 'nginx' to '/run/current-system/sw/bin/nginx'
- Change psql command from 'psql' to '/run/current-system/sw/bin/psql'
- This ensures sudo rules can properly match the commands with full paths

agent/src/collectors/service.rs

@@ -526,7 +526,7 @@ impl ServiceCollector {
 
     async fn get_postgres_connections(&self) -> Option<String> {
         let output = Command::new("sudo")
-            .args(["-u", "postgres", "psql", "-t", "-c", "SELECT count(*) FROM pg_stat_activity WHERE state = 'active';"])
+            .args(["-u", "postgres", "/run/current-system/sw/bin/psql", "-t", "-c", "SELECT count(*) FROM pg_stat_activity WHERE state = 'active';"])
             .stdout(Stdio::piped())
             .stderr(Stdio::piped())
             .output()
@@ -585,10 +585,10 @@ impl ServiceCollector {
             None => {
                 // Fallback to default nginx -T
                 let mut cmd = if self.is_running_as_root() {
-                    Command::new("nginx")
+                    Command::new("/run/current-system/sw/bin/nginx")
                 } else {
                     let mut cmd = Command::new("sudo");
-                    cmd.arg("nginx");
+                    cmd.arg("/run/current-system/sw/bin/nginx");
                     cmd
                 };
                 
@@ -615,10 +615,10 @@ impl ServiceCollector {
         
         // Use the specific config file
         let mut cmd = if self.is_running_as_root() {
-            Command::new("nginx")
+            Command::new("/run/current-system/sw/bin/nginx")
         } else {
             let mut cmd = Command::new("sudo");
-            cmd.arg("nginx");
+            cmd.arg("/run/current-system/sw/bin/nginx");
             cmd
         };