fix(mesh): capture actual esptool/rnodeconf output in the failure error

run_streamed's failure path only reported "Command exited with exit status:
N" — the real stderr (already captured line-by-line into job.log_tail for
the UI's live poll) never made it into the error that gets logged to
journald. A real esptool failure just now showed only the bare exit code,
with esptool's actual error text sitting in-memory, visible in the UI but
not diagnosable from the server logs.

Now includes the last 10 log_tail lines in the returned error, so the
actual tool output shows up in journalctl too.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

core/archipelago/src/mesh/flash.rs

@@ -838,7 +838,23 @@ async fn run_streamed(mut cmd: Command, stdin: Option<Vec<u8>>, job: &Arc<FlashJ
         let _ = t.await;
     }
     if !status.success() {
-        anyhow::bail!("Command exited with {status}");
+        // Exit status alone isn't diagnosable — the actual esptool/rnodeconf
+        // stderr (already captured into job.log_tail by the reader tasks
+        // above) is what actually explains a failure. Confirmed live
+        // 2026-07-23: a bare "Command exited with exit status: 1" told us
+        // nothing when esptool's real error was sitting in the log tail the
+        // whole time, only visible via the UI's live poll, not journald.
+        let tail: Vec<String> = job
+            .snapshot()
+            .await
+            .log_tail
+            .iter()
+            .rev()
+            .take(10)
+            .rev()
+            .cloned()
+            .collect();
+        anyhow::bail!("Command exited with {status}\n{}", tail.join("\n"));
     }
     Ok(())
 }