Wiresheet: arrow nudges keep the selection and the sheet's focus

Ctrl+A hands the sheet the keyboard, and repainting the same sheet keeps
whatever of the selection is still on it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

wiresheet.py

@@ -1234,6 +1234,11 @@ def render_components(components_to_render):
     """Handles parsing and visual painting of given component listings on canvas with slot attributes."""
     canvas = app_state.canvas
     app_state.active_components_list = components_to_render
+    # Repainting the same sheet (a refresh, an undo, a device update) keeps whatever of
+    # the selection is still on it; another sheet starts with nothing selected.
+    kept = [app_state.canvas_comp_map.get(t) for t in app_state.selected_canvas_tags
+            if t != app_state.selected_canvas_tag]
+    kept.append(app_state.canvas_comp_map.get(app_state.selected_canvas_tag))
     app_state.selected_canvas_tag = None
     app_state.selected_canvas_tags.clear()
 
@@ -1275,6 +1280,15 @@ def render_components(components_to_render):
     draw_links()
     apply_sheet_zoom(fonts)
 
+    on_sheet = set(components_to_render)
+    for element in kept:
+        if element is not None and element in on_sheet:
+            tag = app_state.canvas_tag_by_element[element]
+            app_state.selected_canvas_tags.add(tag)
+            app_state.selected_canvas_tag = tag
+    for tag in app_state.selected_canvas_tags:
+        canvas.itemconfig(f"{tag} && block_outline", outline="#1f4e79", width=3)
+
 
 def apply_sheet_zoom(fonts):
     """Scales the finished sheet to app_state.zoom and sizes the canvas to match.