tune: a new plan clears the previous scope's kernel state

consume_event's plan branch set the outer counters but left kernel/phase/inner
counters/live from the scope before it. One relay sees BOTH dasllama halves, so
after the generator half ends, the kernel half's plan left the display showing
"0/25 confirm_e2e_prefill" — and that is not a single frame: tune_kernels has
~30 lines of fixture setup between its plan and its first kernel_begin, so the
wrong kernel name is on screen for all of it.

plan now rebuilds the whole state, which is what a fresh scope means; begin
already did the same for per-kernel fields. Test added for the two-plan
sequence.

Caught by Copilot on #3583.

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

Author: borisbat

modules/dasLLVM/daslib/llvm_tune.das

@@ -1142,11 +1142,12 @@ def private consume_event(line : string; render : bool) {
     }
     let kind = parts[0]
     if (kind == "plan") {
-        g_prog.scope = event_field(parts, "scope", "")
-        g_prog.outerTotal = to_int(event_field(parts, "total", "0"))
-        g_prog.outerDone = 0
-        g_prog.startTicks = ref_time_ticks()
-        g_prog.active = true
+        // a fresh scope: one relay sees both tuner halves, so the previous scope's kernel must go
+        g_prog = TuneProgress(
+            scope = event_field(parts, "scope", ""),
+            outerTotal = to_int(event_field(parts, "total", "0")),
+            startTicks = ref_time_ticks(),
+            active = true)
     } elif (kind == "begin") {
         g_prog.kernel = event_field(parts, "name", "")
         g_prog.innerTotal = to_int(event_field(parts, "total", "0"))

modules/dasLLVM/tests/llvm_tune_progress.das

@@ -110,6 +110,24 @@ def test_a_spaced_value_truncates_but_does_not_corrupt(t : T?) {
     t |> success(line |> find("0/2") >= 0, "the counters are untouched")
 }
 
+// One relay sees both dasllama tuner halves, so a second plan must not inherit the first
+// scope's kernel — there is fixture setup between a plan and its first begin to show it in.
+[test]
+def test_a_new_plan_clears_the_previous_scope(t : T?) {
+    feed_plan(3)
+    tune_progress_feed("@tune begin name=leftover total=9")
+    tune_progress_feed("@tune step i=4 phase=finalists live=7")
+    tune_progress_feed("@tune end name=leftover winner=w verdict=holds")
+    t |> success(tune_progress_line(100) |> find("leftover") >= 0, "still the first scope here")
+    // second half starts; nothing from the first may survive into its opening frame
+    tune_progress_feed("@tune plan scope=second total=7")
+    let line = tune_progress_line(100)
+    t |> success(line |> find("leftover") < 0, "the previous scope's kernel is gone")
+    t |> success(line |> find("finalists") < 0, "and so is its pass")
+    t |> success(line |> find("live") < 0, "and its live count")
+    t |> success(line |> find("0/7") >= 0, "the new plan's counters are in place")
+}
+
 [test]
 def test_verbosity_parses_and_defaults(t : T?) {
     tune_set_verbosity("silent")