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/controller.h

@@ -113,6 +113,7 @@ public:
 
     RcxDocument* document() const { return m_doc; }
     void setEditorFont(const QString& fontName);
+    void setRefreshInterval(int ms);
 
     // MCP bridge accessors
     void setSuppressRefresh(bool v) { m_suppressRefresh = v; }
@@ -121,6 +122,9 @@ public:
     int activeSourceIndex() const { return m_activeSourceIdx; }
     void switchSource(int idx) { switchToSavedSource(idx); }
 
+    // Test accessor
+    const QHash<uint64_t, ValueHistory>& valueHistory() const { return m_valueHistory; }
+
 signals:
     void nodeSelected(int nodeIdx);
     void selectionChanged(int count);