Function update_bubble_position_from_event 

pub fn update_bubble_position_from_event(
    state: &BubbleState,
    physical_x: i32,
    physical_y: i32,
)

Update the bubble window’s in-memory position cache. Called from main.rs’s on_window_event handler whenever the user drags the bubble. Persistence happens on Hide (not on every Moved) to avoid hammering the disk during a drag — per-frame Moved events on macOS would otherwise cause thousands of writes per drag.