Function stability_map 

pub fn stability_map(
    g: &Graph,
    base_cfg: &SheafConfig,
    flow: FlowFn,
    alphas: &[f64],
    times: &[f64],
) -> StabilityMap

Compute a stability map: spectral gap over (alpha, time) grid.

Parameters:

• g: graph topology
• base_cfg: base sheaf config (alpha will be overridden per row)
• flow: flow energy function
• alphas: array of alpha values to scan
• times: array of time points to scan

Returns a StabilityMap with gap_values stored row-major.