Function filtered_install_indices 

pub fn filtered_install_indices(app: &AppState) -> Vec<usize>

What: Produce visible indices into app.install_list with optional pane-find filtering.

Inputs:

• app: Application state (focus, pane_find, install list)

Output:

• Vector of indices in ascending order without modifying application state.

Panics

• Panics if pane_find is Some but becomes None between the check and the expect call (should not happen in single-threaded usage)

Details:

• Restricts matches to name or description substrings when the Install pane is focused and a pane-find expression is active; otherwise surfaces all indices.