User report via the owner: change a marker's size and the icon stays at its
default size — a big empty box around a small glyph. The badge, ripple and
value badges all derive from --dev-size (base size x per-device multiplier),
but --mdc-icon-size was pinned to the BASE --icon-size, so the multiplier
never reached the glyph. One calc argument: --dev-size.
New smoke_icon_scale: at size 3 the glyph grows with the badge and keeps
the 0.62 proportion. Inventory: 147 / 51 / 43 / 69.
