refactor(web): trim every key row's height

Measured at 390x844. The input row was 60px for one line of text and four
icons, and it stayed 60px after `.term-input button:last-child`'s padding was
cut: the `/` and Send buttons carried theirs INLINE, where no stylesheet rule
reaches, and the row is a flex box so every child stretches to the tallest.
Both moved into `.term-cmd` / `.term-send` and the row is 43px. A test now
refuses any inline `padding` under `.term-input`, because that failure is
silent -- the rule looks applied and nothing moves.

Key heights: pad and quick dock 38 -> 34, presets 36 -> 32, digits 44 -> 34,
approval bar 40 -> 32. With the row padding, the keys pad goes 121 -> 111,
presets open 201 -> 183, digits 85 -> 73, quick dock 121 -> 111. Input plus
keys pad is 154px of an 844px phone, against 265px before this series. No
label clips down to a 320px viewport, at 40px a cell.

Found while measuring: `key-green` / `key-blue` / `key-red` -- the single-letter
form of the three approval answers -- had no CSS whatsoever, rendering as
11x19px native buttons in Chrome's own grey, unthemed, in the middle of a dark
dock. `#actionKeys` is now a 3-column grid of 30px keys tinted from the same
accents as the answers above them. That costs the dock 14px while a pane is
blocked, which is the price of three targets a thumb can actually hit.