feat: fix heatmap false-heat on offset shift, hover flicker, type chooser cleanup

- Clear value history when node offsets change (insert/delete/resize/
  manual offset edit) so stale values from old addresses don't show
  false heat coloring
- Invalidate in-flight async reads (bump refreshGen) when tree layout
  changes, preventing stale snapshot data from re-introducing heat
- Fix command bar hover cursor flicker: remove premature
  applyHoverCursor() from applyDocument() — runs correctly via
  applySelectionOverlays() after text is finalized
- Fix hover indicator survival: reorder refresh() so text-modifying
  passes (updateCommandRow) run before overlay passes
- Guard synthetic Leave events during setText() to preserve hover state
- Remove primitives from type chooser when pointer modifier (* / **)
  is active; remove primitives entirely in Root command bar mode
- Add test_editor and test_controller test coverage for heat clearing,
  hover survival, and mixed hex/non-hex type scenarios

src/themes/theme.cpp

@@ -54,9 +54,9 @@ Theme Theme::fromJson(const QJsonObject& o) {
             t.*kThemeFields[i].ptr = QColor(o[kThemeFields[i].key].toString());
     }
     // Derive heat colors from the theme's own palette when keys are absent
-    // cold = keyword blue, warm = hover/string amber, hot = marker red
+    // cold = muted yellow, warm = hover/string amber, hot = marker red
     if (!t.indHeatCold.isValid())
-        t.indHeatCold = t.syntaxKeyword;
+        t.indHeatCold = QColor("#D4A945");
     if (!t.indHeatWarm.isValid())
         t.indHeatWarm = t.indHoverSpan.isValid() ? t.indHoverSpan : t.syntaxString;
     if (!t.indHeatHot.isValid())