- Extract drawBoxedIcon()/drawSlotIcon() in icons.h; collapse the four
near-identical mute/BT/advert/trail blocks in renderBatteryIndicator.
- Centre the glyph on the actual indicator box (box_h) instead of the text
line, fixing the 1px vertical offset in Lemon mode.
- Extract blinkOn() for the shared advert/trail blink cadence.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>