tune: a must-see line no longer collides with the live display

report()'s "no passing variant" printed straight to stdout while the bar was
live, so it landed on the bar's line and the next redraw wrote over it — the one
message you must not lose was the one most likely to be destroyed.

Routing it through tune_detail (the obvious fix) would be worse: that mutes
under normal verbosity, so a hard failure would vanish entirely. Added
tune_progress_note instead — it wipes the bar's line, prints the text, and
leaves the display armed so the bar redraws underneath. Silent still suppresses.

Verified on a pty by replaying the CR/LF stream the way a terminal does:
    k0: no passing variant
  [######--------------] 1/3  k1  finalists 2/4  4 live  0s

Copilot also flagged the summary block for the same reason; that one is fine —
it runs after tune_progress_finish() has already closed the display.

Caught by Copilot on #3583.

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

Author: borisbat

modules/dasLLAMA/harness/tune_kernels.das

@@ -224,7 +224,7 @@ def report(kernel : string; names : array<string>; best : array<double>; ok : ar
         tune_detail("  {names[i]}: {best[i]} us  ({delta}% vs {baseline}){mark}\n")
     }
     if (winner < 0) {
-        print("  {kernel}: no passing variant\n")
+        tune_progress_note("  {kernel}: no passing variant\n")
         tune_progress_kernel_end(kernel, "", "rejected")
         g_results |> emplace(KernelResult(kernel = kernel, winner = "", fallback = baseline))
         return ""

modules/dasLLVM/daslib/llvm_tune.das

@@ -1198,6 +1198,24 @@ def tune_detail(text : string) {
     print(text)
 }
 
+//! Print a line that must be seen even while a display is live — a failure, not chatter. Wipes
+//! the bar's line first so the text is not written over it, and leaves the display armed so the
+//! next event redraws the bar underneath. Use `tune_detail` for anything mutable.
+def tune_progress_note(text : string) {
+    if (tune_verbosity() == "silent") return
+    if (g_prog.drawn) {
+        let cols = terminal_columns()
+        let wipe = build_string() $(w) {
+            for (_i in range(max(0, cols - 1))) {
+                w |> write(" ")
+            }
+        }
+        print("\r{wipe}\r")
+        g_prog.drawn = false
+    }
+    print(text)
+}
+
 //! Close a live display, so whatever prints next starts on its own line. A tuner that emitted
 //! progress calls this before it returns; the relay does it automatically when a child exits.
 def tune_progress_finish() {