Resume-prompt Option F, part 1 of 2. Adds two accessibility flags
to Settings and threads each through the engine surfaces that
react to them. Settings UI toggle rows follow in a separate
commit; players who want to test today can edit `settings.json`
manually.
Spec at `docs/ui-mockups/design-system.md` §Accessibility (#2 and
#3).
### High-contrast mode
`Settings::high_contrast_mode: bool` (defaults to false; serde-
default for back-compat). When on:
- Red-suit text colour boosts from `RED_SUIT_COLOUR` (`#fb9fb1`)
to a new `RED_SUIT_COLOUR_HC` (`#ff8aa0`).
- Black-suit text colour boosts from `BLACK_SUIT_COLOUR`
(`#d0d0d0`) to a new `TEXT_PRIMARY_HC` (`#f5f5f5`).
- New `BORDER_SUBTLE_HC` (`#a0a0a0`) constant available for
future chrome-side wiring (this commit only routes HC through
card text rendering — chrome border boost is a separable
follow-up).
The HC and CBM flags compose. CBM red→lime wins over HC on red
suits when both are on (lime is itself a high-luminance accent,
so the HC boost has nothing further to do). HC still applies to
black suits when both flags are on (CBM doesn't touch black).
Four new `text_colour` tests pin the truth table.
### Reduce-motion mode
`Settings::reduce_motion_mode: bool` (defaults to false; serde-
default for back-compat). When on:
- Card-slide animation duration is forced to `0.0` regardless of
the player's `AnimSpeed` selection — cards snap instantly to
their target position. Implemented by extracting a new
`effective_slide_secs(&Settings)` helper that wraps
`anim_speed_to_secs` with the reduce-motion gate.
- Future scaffolding hooks (splash scanline, warning-chip pulse,
card-lift z-bump animation) follow the same `if
settings.reduce_motion_mode { skip }` pattern when wired —
stays out of scope for this commit since each motion path
needs its own per-system gate.
Two new tests cover the gate behaviour and the fall-through-to-
AnimSpeed pass-through path.
### Threading
`text_colour` signature extended with a `high_contrast: bool`
parameter; `sync_cards` / `sync_cards_startup` /
`sync_cards_on_change` / `sync_cards` core / `spawn_card_entity`
/ `update_card_entity` all gain a parallel parameter mirroring
the existing `color_blind: bool` plumbing. Verbose but matches
the established pattern; a future refactor could pack both into
an `AccessibilityView` struct, but bigger blast radius.
### Stats
1191 passing / 0 failing across the workspace (net +6 from
v0.21.0's 1185 baseline once the icon-pin test landed):
- 4 new `text_colour` HC tests in `card_plugin`
(red-suit boost, black-suit boost, CBM-wins-on-red,
black-suits-with-CBM+HC-still-boost).
- 2 new `effective_slide_secs` tests in `animation_plugin`
(zero-out under reduce-motion, fall-through to AnimSpeed when
off).
`cargo clippy --workspace --all-targets -- -D warnings` clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
funman300
c5787c6953