[Feature Request] Add custom label anchor for Sankey graphs

Add the possibility to custom change the anchor of the node text

Current:

After:

Minimum example code:

import dash
from dash import dcc, html, Input, Output
import plotly.graph_objects as go

# Inicializa o app Dash
app = dash.Dash(__name__)
app.title = "Sankey Colorido"

# ----------- Sankey básico -------------
labels = ["A1", "A2", "B1", "B2", "C1", "C2"]
sources = [0, 1, 0, 2, 3, 3]
targets = [2, 3, 3, 4, 4, 5]
values  = [8, 4, 2, 8, 4, 2]

fig = go.Figure(go.Sankey(
    arrangement="snap",
    node=dict(
        pad=15,
        thickness=20,
        line=dict(color="black", width=0.5),
        label=labels,
        color="blue"
    ),
    link=dict(
        source=sources,
        target=targets,
        value=values
    )
))

fig.update_layout(title_text="Basic Sankey Diagram", font_size=10)

# ----------- Layout Dash -------------
app.layout = html.Div([
    dcc.Graph(
        id="sankey-graph",
        figure=fig,
        style={"width":"100%", "height":"100vh"}
    )
])

# ----------- Client-side callback para alinhar labels -------------
# desloca horizontalmente e alinha à direita
app.clientside_callback(
    """
    function(figure) {
        setTimeout(() => {
            const labels = document.querySelectorAll('.sankey .node-label');
            labels.forEach(label => {
                const transform = label.getAttribute('transform');
                const match = /translate\\(([^,]+),([^)]+)\\)/.exec(transform);
                if(match){
                    const y = parseFloat(match[2]);
                    const x = -15; // deslocamento horizontal
                    label.setAttribute('transform', `translate(${x},${y})`);
                    label.setAttribute('text-anchor','end'); // alinhamento à direita
                }
            });
        }, 500); // espera renderização
        return figure;
    }
    """,
    Output('sankey-graph', 'figure'),
    Input('sankey-graph', 'figure')
)

if __name__ == "__main__":
    app.run(debug=True)

The clientside_callback is replaced after user interaction with the graph

El issue no nombra ningún archivo del repositorio ni ninguna prueba. Empieza rastreando la representación de las etiquetas de los nodos Sankey en plotly.js y compárala con la solución alternativa basada en un callback clientside; estará hecho cuando un anclaje de etiqueta personalizado compatible sobreviva a la interacción con el gráfico sin esa solución alternativa.