[3.0] Theme split (wave 4, part 30) — point the toggles and small icons at design tokens

[albertlast]

Description

Part of the #7933 split.

The collapse and expand toggle and its hover state, the message icon picker, and the green and grey dots that mark a member online or offline. 23 tokens. Every token holds the value the rule has today, so nothing renders differently.

The toggle's three-part box-shadow becomes one token rather than three, since the three shadows are one effect and are never set apart.

Verification

Every rule in index.css parsed out of the file as text, applied to a probe, read back as a fixed list of 57 longhands:

965 rules, 55,005 computed values, 0 differences.

That includes the reformatting of the toggle's multi-line shadow into a single-line token value, and rgba(0,0,0,.1) being written with spaces — both normalise to the same computed value, which is what the count above shows.

Issues References (Fixes|Related|Closes)

Related: #7933

[albertlast]

Re-ran the verification, because the first run was taken on ?topic=1.0 and that page is a fatal on release-3.0 — Object of type SMF\TimeInterval (inheriting DateInterval) has not been correctly initialized by calling parent::__construct(), which is #9405 and not merged yet. An error page still loads variables.css, and base and branch were captured in the same state, so the comparison held; but it is not a measurement anyone should have to take on trust.

Repeated on ?action=recent, which renders, with the capture now recording the page URL, whether #fatal_error is present, and the list of loaded stylesheets so a broken page cannot pass unnoticed:

OK  page=/index.php?action=recent fatal=False  965 rules, 55005 values, diffs 0

Same result. No change to the diff.