fix(browser): surface actual camoufox-bridge error on daemon start failure

trigger_daemon_start now captures stdout/stderr and exit code instead
of silently redirecting to a log file. On failure it prints the actual
error, making it obvious what went wrong (npm install issue, node
version mismatch, etc.).

crates/gyandoot-agent/src/browser_manager.rs

@@ -18,7 +18,6 @@
 //!    `/home/user/.nvm/versions/node/v22/bin/npx`)
 //! 2. `"npx"` on Linux/macOS, `"npx.cmd"` on Windows — PATH lookup
 
-use std::process::Stdio;
 use std::time::Duration;
 
 use tokio::process::Command;
@@ -136,24 +135,55 @@ async fn trigger_daemon_start(session: &str, node_path: Option<&str>) -> Result<
         .map_err(|e| format!("Cannot create {}: {}", log_dir.display(), e))?;
     let log_file = log_dir.join("camoufox-daemon-spawn.log");
 
-    let log = std::fs::File::create(&log_file)
-        .map_err(|e| format!("Cannot create log file: {}", e))?;
-
     let npx = resolve_npx(node_path);
 
     // Run a command — the CLI auto-starts the daemon as a side effect
-    let _output = Command::new(npx)
+    let output = Command::new(npx)
         .args(&[
             "camoufox-browser@latest",
             "tab_list",
             "--session", session,
         ])
-        .stdout(Stdio::from(log.try_clone().map_err(|e| e.to_string())?))
-        .stderr(Stdio::from(log))
         .output()
         .await
-        .map_err(|e| format!("{} failed: {}. Is Node.js installed?", npx, e))?;
+        .map_err(|e| {
+            let hint = if node_path.is_none() {
+                "\n  → Set [browser].node_path in your config, e.g.:\n    [browser]\n    node_path = \"/Users/yourname/.nvm/versions/node/v22/bin/npx\"".to_string()
+            } else {
+                format!("\n  → npx at '{}' not found or not executable", npx)
+            };
+            format!("{} failed: {}. Is Node.js installed?{}", npx, e, hint)
+        })?;
 
+    if !output.status.success() {
+        // Read the log for details
+        let stderr = String::from_utf8_lossy(&output.stderr).trim().to_string();
+        let stdout = String::from_utf8_lossy(&output.stdout).trim().to_string();
+        let details = if !stderr.is_empty() { stderr.clone() } else { stdout.clone() };
+
+        // Also save to log file for reference
+        let _ = std::fs::write(&log_file, format!(
+            "exit_code: {}\nstdout:\n{}\nstderr:\n{}\n",
+            output.status.code().unwrap_or(-1),
+            stdout, stderr
+        ));
+
+        let hint = if node_path.is_none() {
+            "\n  → Try setting [browser].node_path in your config:\n    [browser]\n    node_path = \"/Users/yourname/.nvm/versions/node/v22/bin/npx\"".to_string()
+        } else {
+            String::new()
+        };
+
+        return Err(format!(
+            "camoufox-browser failed (exit: {}):\n  {}\n  → Full log saved to {}{}",
+            output.status.code().unwrap_or(-1),
+            details,
+            log_file.display(),
+            hint,
+        ));
+    }
+
+    // Command succeeded — daemon should be starting
     Ok(())
 }