debug(smart v0.1.12): logging détaillé pour diagnostiquer smart=nil

Logs étape par étape : détection devices, exit code smartctl,
taille stdout/stderr, résultat parse JSON.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

agent/Cargo.lock

@@ -248,7 +248,7 @@ dependencies = [
 
 [[package]]
 name = "nanometrics-agent"
-version = "0.1.11"
+version = "0.1.12"
 dependencies = [
  "libc",
  "rumqttc",

agent/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "nanometrics-agent"
-version = "0.1.11"
+version = "0.1.12"
 edition = "2021"
 
 [lib]

agent/src/metrics/smart.rs

@@ -82,6 +82,7 @@ pub fn parse_json(json: &str) -> Result<crate::payload::SmartMetrics, serde_json
 
 pub fn collect() -> Option<Vec<crate::payload::SmartMetrics>> {
     if !is_available() {
+        eprintln!("[smart] smartctl introuvable dans PATH");
         return None;
     }
     let mut devs: Vec<String> = std::fs::read_dir("/sys/block")
@@ -91,11 +92,8 @@ pub fn collect() -> Option<Vec<crate::payload::SmartMetrics>> {
         .map(|e| e.file_name().into_string().unwrap_or_default())
         .filter_map(|n| {
             if n.starts_with("sd") {
-                // /dev/sda, /dev/sdb — block device, groupe disk OK
                 Some(format!("/dev/{}", n))
             } else if n.starts_with("nvme") && n.contains('n') {
-                // /dev/nvme0n1 — block device (brw-rw---- root disk), groupe disk OK
-                // NE PAS utiliser /dev/nvme0 (contrôleur crw------- root root, root only)
                 Some(format!("/dev/{}", n))
             } else {
                 None
@@ -105,19 +103,33 @@ pub fn collect() -> Option<Vec<crate::payload::SmartMetrics>> {
         .into_iter()
         .collect();
     devs.sort();
+    eprintln!("[smart] disques détectés: {:?}", devs);
 
     let mut results = Vec::new();
     for dev in &devs {
-        let Ok(output) = std::process::Command::new("smartctl")
+        let output = match std::process::Command::new("smartctl")
             .args(["-a", "-j", dev])
-            .output() else { continue };
+            .output()
+        {
+            Ok(o) => o,
+            Err(e) => { eprintln!("[smart] erreur exec smartctl {}: {}", dev, e); continue }
+        };
+        eprintln!("[smart] smartctl {} → exit={}, stdout={} octets, stderr={} octets",
+            dev, output.status, output.stdout.len(), output.stderr.len());
         let json = String::from_utf8_lossy(&output.stdout);
-        if let Ok(metrics) = parse_json(&json) {
+        match parse_json(&json) {
+            Ok(metrics) => {
+                eprintln!("[smart] {} parsé OK (passed={})", dev, metrics.passed);
                 results.push(crate::payload::SmartMetrics {
                     device: dev.trim_start_matches("/dev/").to_string(),
                     ..metrics
                 });
             }
+            Err(e) => {
+                eprintln!("[smart] {} parse JSON échoué: {}", dev, e);
+                eprintln!("[smart] premiers 200 octets stdout: {:?}", &json.chars().take(200).collect::<String>());
+            }
+        }
     }
     if results.is_empty() { None } else { Some(results) }
 }