web/components: keep Button one height with or without a label
The size variants' min-h values are the Figma button heights (32/36/40),
but line-height plus py-1.5 and the 1px border already exceeded them, so
the floor only ever applied to icon-only buttons. A labelled button came
out 2-5px taller than an icon-only one beside it. Dropping to py-1 keeps
content under the min-h at every size; the padding still acts as the
floor if a label wraps.
Signed-off-by: eti <eti@eti.tf>