fix: serialization of box/lasso select data for multiple subplots - #5710

"""
Test script to verify subplot-specific selector keys are preserved.

Run with:
  solara run test_subplot_selection.py

Then:
1. Click "Box Select" tool in the toolbar
2. Make a selection in the SECOND subplot (Bar chart) - NOT the first one
3. Check the console output for the selector data
4. Verify that x2range and y2range (or similar x2, y2 keys) are present in selector_state
"""

import plotly.graph_objects as go
import solara
from plotly.subplots import make_subplots
import json


def build_figure() -> go.Figure:
    fig = make_subplots(rows=1, cols=2, subplot_titles=("Scatter", "Bar"))
    fig.add_trace(
        go.Scatter(x=[1, 2, 3, 4, 5, 6], y=[2, 1, 3, 5, 4, 6], name="Series A"),
        row=1,
        col=1,
    )
    fig.add_trace(
        go.Bar(x=["A", "B", "C"], y=[3, 1, 2], name="Series B"), row=1, col=2
    )
    fig.update_layout(title="FigureWidget example with 2 subplots")
    return fig


@solara.component
def Page():
    selection_data, set_selection_data = solara.use_state(None)
    def on_selection(data):
        set_selection_data(data)
    with solara.Column():
        solara.FigurePlotly(build_figure(), on_selection=on_selection)
        if selection_data:
            with solara.Column():
                solara.Markdown("### Last Selection Data (Pretty-printed)")
                solara.Markdown(
                    f"```json\n{json.dumps(selection_data, indent=2, default=str)}\n```"
                )