Fix icon size and padding mismatch between initial and hover states

[jasPreMar]

Summary

• The app icon displayed when first invoking the hotkey (20x20 with uniform 8px padding in a 36x36 square) was inconsistent with the icon shown when hovering over apps in command key mode with object text off (16x16 with asymmetric padding in a 44px container).
• Unified the hover-state icon to match the initial indicator: 20x20 icon, uniform padding(8), and 36px container width.

Test plan

• swift run ThisTests — 102 passed, 0 failed
• Invoke hotkey, confirm icon appears as a centered square
• Move cursor to hover over different apps with object text off — icon should remain the same size with even spacing

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