Redesign remember-my-choice checkbox in WAYF

[kayjoosten]

What

Implements #2066, redesigning the WAYF "remember my choice" checkbox to
match the new visual design (checkbox before label, adjusted margins,
plain black text instead of bold blue) and adding an accessible tooltip
on the per-SP variant explaining how long a choice is remembered and
how to reset it.

Stacked on #2094

This branches from wayf-reset-endpoint (#2094, not yet merged), since
the tooltip copy links to the reset endpoint added there, and the
per-SP flag/config this ticket builds on comes from #2065 (#2091). The
diff shown here is the incremental change for #2066 only; once #2091
and #2094 merge to main, this PR's base should be retargeted to
main.

Details

• rememberChoice.html.twig is reordered so the checkbox comes before
  its label, and now branches on rememberChoicePerIdp: the per-SP
  variant shows duration-aware copy ("remembered for 90 days") plus a
  tooltip toggle, while the global variant keeps its existing text
  unchanged.
• The tooltip reuses the same checkbox-toggle + CSS sibling-selector
  pattern as Consent/Attributes/tooltip.html.twig, so no new
  JavaScript is needed — wayf/mouseBehaviour.js's existing
  handleAriaPressed() already runs on every WAYF page load and
  handles the aria-pressed/aria-expanded toggling generically.
• rememberChoicePerIdp and rememberChoiceDuration were already
  threaded through WayfViewModel/WayfViewModelFactory/WayfRenderer
  for Remember choice for WAYF per SP #2065 but never reached the template — a real pre-existing gap.
  wayf.html.twig and remainingIdps.html.twig now forward both
  values into rememberChoice.html.twig.
• New RememberChoiceDurationFormatter turns
  wayf.remember_choice_per_idp_lifetime (seconds) into a translated
  "N days"/"N minutes" string. WayfViewModelFactory only computes it
  when rememberChoicePerIdp is true, so the translator isn't invoked
  on every WAYF render for SPs using the global (non-per-SP) cookie.
• New translation keys were added to languages/messages.{en,nl,pt}.php
  rather than theme/*/translations, matching where the existing
  remember_choice key already lives.
• WayfController's functional-testing fixture gained a
  rememberChoicePerIdp query param (defaulting to false, preserving
  existing behaviour for all current callers) so both variants can be
  exercised manually and from Cypress.
• New Cypress coverage in wayf.general.spec.js checks that the per-SP
  checkbox and tooltip toggle render and function correctly, and that
  the global variant has no tooltip element.

Note: pre-existing it.only in wayf.general.spec.js

This spec file has a pre-existing it.only('Shows the global site notice', ...) (predates this branch) that currently suppresses every
other test in the file when run locally/in CI. I verified this is
unrelated to my changes: temporarily removing it against the
unmodified base branch reproduces the same 12 pre-existing failures
(IdP count/search assertions), and with it removed my 5 new tests all
pass cleanly. I left it in place per the minimal-diff policy, but
flagging it here since it means the new Cypress tests (and the rest of
this file) aren't currently exercised by CI as things stand — worth a
follow-up ticket to fix the underlying flakiness and remove .only.

Testing

All run inside the Docker dev container (PHP 8.5):

• phpmd / phpcs / phpcs-legacy / docheader: clean.
• eb4: 244/244. unit: 1013/1013 (1003 baseline + 10 new).
  functional (APP_ENV=test): 121/121. integration: 105/105.
• Behat default suite: 300/300 scenarios, 5557/5557 steps.
• Twig lint: 115/115. yarn lint: clean.
• Cypress (wayf.general.spec.js, firefox headless, with the
  pre-existing it.only temporarily removed for verification only):
  new tests pass; the 12 pre-existing failures are unchanged from the
  base branch (see note above).

Refs: #2066