Say Remove for displays, and make the default accent purple (#210050)

Administrators now remove a display: the card's Remove, "Remove display?",
and "Display removed". The platform still revokes the device's credential;
the endpoint, fields, and security history keep revoke/revoked (ADR 0065).

The default accent is a deep purple anchored on #210050, set in the shared
design tokens only (ADR 0066, superseding ADR 0060's teal in part). The
anchor is the light primary action with white on it; the light accent text,
focus ring, and selection, and the dark theme's lavender accent, are
variants on its hue chosen for contrast. The teal-tinted neutrals move to a
faint violet-grey at the same lightness, so every contrast pairing holds.
The contrast test gains six pairings the accent depends on, and pins the
anchor.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

docs/architecture/decisions/0066-default-purple-accent.md

@@ -0,0 +1,112 @@
+# 0066: The default accent is a deep purple anchored on `#210050`
+
+- Status: Accepted
+- Date: 2026-10-16
+- Supersedes, in part: [0060](0060-light-dark-system-theme-and-motion.md) (the teal accent and the
+  teal-tinted charcoal of its designed dark theme)
+- Extends: [0039](0039-shared-design-tokens-and-elements.md),
+  [0060](0060-light-dark-system-theme-and-motion.md)
+
+## Context
+
+Ekklesia's default theme was accented in teal. The light primary action was a pale teal (`#4fb3a8`)
+with dark text on it. ADR 0060's designed dark theme described "teal-tinted charcoal" backgrounds and
+"the same teal accent, slightly lifted". The neutrals carried the same teal tint, so did the
+selection and information washes, and the whole product read as teal.
+
+The maintainer chose a purple default anchored on `#210050`. Branding settings will later let an
+administrator choose the accent. This decision changes only the **default**.
+
+A single hex cannot serve every place the accent is used. `#210050` is very dark: it is 17.8:1
+against white, but about 1.2:1 against a dark-theme page, where it would all but vanish.
+
+## Decision
+
+### The accent is set through the semantic tokens only
+
+The change is made in `@ekklesia/design-tokens`' registry, and nowhere else. No Dashboard component
+names a purple. The shared `@ekklesia/ui` elements and the shell already draw from `accent.*`,
+`state.selected-*`, and `status.info-*`, so they inherit the new values. Modules read the same
+`--ekklesia-*` custom properties (ADR 0040), so their token inheritance is unchanged.
+
+### `#210050` is the light primary action; every other value is a variant on its hue
+
+Each variant keeps the anchor's OKLCH hue (≈291.5°). Lightness and chroma are chosen for contrast
+where the variant is used.
+
+| Token | Light | Dark | Used for |
+| --- | --- | --- | --- |
+| `accent.base` | **`#210050`** | `#ac9bf6` | primary button, tab underline, spinner, brand mark |
+| `accent.hover` | `#340e71` | `#bbacff` | hovered primary button |
+| `accent.active` | `#120033` | `#9a88e2` | pressed primary button |
+| `accent.foreground` | `#ffffff` | **`#210050`** | text on the accent |
+| `accent.strong` | `#4d2a99` | `#c8bcff` | accent text and icons; checked box and radio |
+| `accent.subtle` | `#f0eeff` | `#2e2849` | selected tab wash |
+| `accent.focus` | `#6a40c9` | `#bfb0ff` | focus ring |
+| `state.selected-background` | `#eceaff` | `#342b53` | the open page in navigation, selected option |
+| `state.selected-foreground` | `#48278e` | `#d7d0ff` | its label |
+| `status.info-background` | `#f1f0ff` | `#292440` | information notice and badge |
+| `status.info-border` | `#c7c0f2` | `#564b83` | its border |
+
+**The light theme turns around.** A pale accent with dark text becomes the deep anchor with white
+text: 17.8:1, or 14.5:1 hovered.
+
+**Light accent text and the focus ring stay off the anchor itself.** In body copy `#210050` is
+almost indistinguishable from near-black text, so accent text and icons use a brighter `#4d2a99`
+(10.0:1 on a surface). The focus ring uses a vivid `#6a40c9` (6.1:1 on the page). Next to a dark
+primary button, a ring in the anchor's own colour would merge into the button; this one is clearly
+distinct.
+
+**Dark keeps ADR 0060's principle: lifted, not glowing.** The accent is a lavender (`#ac9bf6`). The
+anchor is drawn on it as its foreground, at 7.4:1, and at 5.9:1 pressed. Selected and information
+washes are deep purple tints, never saturated fills.
+
+### The neutrals lose their teal tint
+
+Every teal-tinted neutral moves to the anchor's hue at the same OKLab lightness and chroma. This
+covers the backgrounds, text, borders, hover and pressed washes, the placeholder, the shadows'
+colour, and the dark overlay.
+
+- **Light:** a faint violet-grey (page `#f6f5f9`, text `#201f28`).
+- **Dark:** a violet-grey charcoal (page `#141319`, text `#eaeaf1`).
+
+ADR 0060's other rules still hold: never pure black, never pure white, and an elevation ladder.
+
+Because lightness is kept, contrast is kept. The tightest pairings move by less than 0.1. For
+example, `border.control` on the light page goes from 3.24 to 3.28, and `text.muted` on the light
+page from 5.04 to 5.10. Success, warning, and danger keep their own hues.
+
+### Contrast stays tested
+
+`packages/design-tokens/tests/contrast.test.ts` keeps all 41 pairings it already checked, in both
+schemes. It adds six pairings this accent depends on:
+
+- the accent as a non-text indicator on the page, the canvas, and a surface;
+- the selected tab's label on its wash;
+- accent text in a dialog;
+- the mark inside a checked box or radio.
+
+A test also pins the anchor: `accent.base` is `#210050` with white on it in light, and in dark it is
+lifted, with the anchor as its foreground.
+
+## Alternatives
+
+- **The same hex everywhere.** Rejected: `#210050` fails as an indicator on dark surfaces at about
+  1.2:1. As light text, it is too close to the body copy to read as an accent.
+- **Purple accent tokens, teal-tinted neutrals.** Rejected: the teal stays visible in every surface
+  and border, most of all in dark, and clashes with the accent.
+- **Hue-rotating every accent token at its old lightness and chroma.** Rejected for the accent
+  tokens: teal's low chroma gives a dull grey-purple. It is used for the neutrals, where a faint
+  tint is the point.
+- **Waiting for Branding settings.** Rejected by the maintainer: the default should be right before
+  anyone configures it.
+
+## Consequences
+
+- Every first-party surface turns purple from tokens alone: the Dashboard, the sign-in pages, and
+  the shared elements. The display host stays light (ADR 0060) and takes the light values.
+- Modules that use the shared tokens, such as Signage, follow the new default with no change of
+  their own. A module that hard-coded the old teal would not, which is why no module should.
+- A deployment that overrides tokens at its host root is unaffected.
+- When Branding settings arrive, the accent becomes an administrator's choice. That feature must
+  derive the same set of variants and pass the same contrast tests. This decision is its default.