Add zoom support to OxPage editor with 50% default

Toolbar zoom buttons (in/out/reset/fit) and Ctrl+MouseWheel now
control the page editor canvas when it is active. Frame image is
scaled via PIL for smooth rendering at any zoom level.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

main.py

@@ -366,6 +366,7 @@ def show_ox_page_view(comp):
     )
     ox_page_panel.frame.pack(fill=tk.BOTH, expand=True)
     record_visit(VIEW_PAGE, comp)
+    update_zoom_label()
     app_state.set_status(f"Page Editor: {comp.get('name', '?')}")
 
 
@@ -377,6 +378,7 @@ def dismiss_ox_page_view(restore_canvas=True):
 
     ox_page_panel.destroy()
     ox_page_panel = None
+    update_zoom_label()
 
     if restore_canvas:
         _give_editor_pane_back()
@@ -617,7 +619,11 @@ def do_tidy_layout(event=None):
 
 def update_zoom_label():
     """Puts the painted scale on the toolbar as a percentage."""
-    if zoom_label is not None:
+    if zoom_label is None:
+        return
+    if ox_page_panel is not None:
+        zoom_label.config(text=f"{round(ox_page_panel.zoom * 100)}%")
+    else:
         zoom_label.config(text=f"{round(app_state.zoom * 100)}%")
 
 
@@ -655,16 +661,28 @@ def zoom_to(level, anchor=None):
 
 
 def do_zoom_in(event=None):
+    if ox_page_panel is not None:
+        ox_page_panel.set_zoom(ox_page_panel.zoom_step(1))
+        update_zoom_label()
+        return "break"
     zoom_to(wiresheet.zoom_step(1))
     return "break"
 
 
 def do_zoom_out(event=None):
+    if ox_page_panel is not None:
+        ox_page_panel.set_zoom(ox_page_panel.zoom_step(-1))
+        update_zoom_label()
+        return "break"
     zoom_to(wiresheet.zoom_step(-1))
     return "break"
 
 
 def do_zoom_reset(event=None):
+    if ox_page_panel is not None:
+        ox_page_panel.set_zoom(1.0)
+        update_zoom_label()
+        return "break"
     zoom_to(1.0)
     return "break"
 
@@ -675,6 +693,15 @@ def do_zoom_fit(event=None):
     The fitted scale is not one of the ladder's, so the percentage on the toolbar is
     where it is read off; stepping in or out from there rejoins the ladder.
     """
+    if ox_page_panel is not None:
+        level = ox_page_panel.fit_zoom_level()
+        if level is None:
+            app_state.set_status("Cannot fit — page editor canvas not ready.")
+            return "break"
+        ox_page_panel.set_zoom(level)
+        update_zoom_label()
+        return "break"
+
     canvas = app_state.canvas
     level = wiresheet.fit_zoom_level()
     bounds = wiresheet.sheet_content_bounds()
@@ -686,8 +713,6 @@ def do_zoom_fit(event=None):
     applied = wiresheet.set_zoom(level)
     update_zoom_label()
 
-    # Bring the sheet's own top-left corner to the top-left of the view, since a fitted
-    # sheet is measured from there rather than from the canvas origin.
     region = str(canvas.cget("scrollregion")).split()
     if len(region) == 4:
         span_x = float(region[2]) or 1.0