GNOME Shell UI bug: 4-billion-pixel height value collapsed ScrollView to 1px

A developer debugging a GNOME Shell extension on Ubuntu 22.04 discovered that a child actor was reporting a preferred height of 4,294,967,296 pixels — near the 32-bit float precision boundary — causing its parent St.ScrollView container to collapse to just 1px and become invisible. The extension loaded without errors, making the layout failure difficult to trace through standard debugging methods. Using a recursive Clutter Actor Tree inspection function, the developer identified which container was producing the erroneous height value. The root cause was linked to conflicting x_expand and y_expand alignment rules, and the fix involved assigning geometry ownership cleanly to a single actor. The investigation highlights how floating-point precision limits near 2^32 can silently break UI layouts in GJS-based GNOME Shell extensions.