refactor(color-picker): stamp current-color in soma trigger (audit 5.3 P1)

Eliminates `Provider.require()` from eidos `<ColorPicker.Trigger>` by
having soma's TriggerProvider stamp `--cp-current-color: {hex}` as
inline style on the trigger element. Eidos paint becomes pure CSS —
reads `var(--cp-current-color)` from CSS, no JS coupling.

Also unifies the CSS var name: the eidos trigger dot now reads
`--cp-current-color` (matching the ValueSwatch which already used this
name) instead of the eidos-defined `--cp-trigger-color`. One canonical
"current colour" var across the component.

Test result unchanged: 2391/2397 passing. No regressions.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/uix/eidos/components/color-picker/color-picker-trigger.svelte

@@ -1,7 +1,12 @@
 <script lang="ts">
+	/**
+	 * Eidos `<ColorPicker.Trigger>` — pure paint wrapper. Soma owns the
+	 * current value and stamps `--cp-current-color` as inline style; this
+	 * wrapper just adds visual data-attrs + the swatch dot. CSS reads the
+	 * var to tint the dot.
+	 */
 	import { ActiveEidos } from '$uix/eidos';
 	import * as ColorPicker from '$soma/components/color-picker';
-	import { ColorPickerProvider } from '$soma/components/color-picker';
 	import { getColorPickerVisualContext } from './context.svelte';
 	import type { ColorPickerTriggerProps } from './types';
 
@@ -20,17 +25,6 @@
 	const resolvedSize = $derived(eidos.resolve(size ?? visual?.getSize() ?? 'md', 'md'));
 	const resolvedVariant = $derived(variant ?? visual?.getVariant() ?? 'surface');
 	const resolvedColor = $derived(color ?? visual?.getColor() ?? 'primary');
-
-	const provider = ColorPickerProvider.require();
-	// Expose the current value to CSS so the trigger swatch dot tints itself.
-	const swatchStyle = $derived(
-		showSwatch
-			? `--cp-trigger-color: ${provider.opts.value.current?.hex ?? 'transparent'}`
-			: ''
-	);
-	const composedStyle = $derived(
-		[swatchStyle, style as string | undefined].filter(Boolean).join('; ')
-	);
 </script>
 
 <ColorPicker.Trigger
@@ -39,7 +33,7 @@
 	data-variant={resolvedVariant}
 	data-color={resolvedColor}
 	data-show-swatch={showSwatch ? '' : undefined}
-	style={composedStyle}
+	{style}
 >
 	{#if showSwatch}
 		<span class="color-picker-trigger-swatch" aria-hidden="true"></span>

src/uix/eidos/components/color-picker/color-picker.css

@@ -161,8 +161,9 @@
 	opacity: var(--color-picker-disabled-opacity);
 }
 
-/* Trigger swatch dot — paints with `--cp-trigger-color` on top of a
+/* Trigger swatch dot — paints with `--cp-current-color` on top of a
-   transparency checker so alpha < 1 reveals the checker beneath. */
+   transparency checker so alpha < 1 reveals the checker beneath. Soma's
+   ColorPickerTriggerProvider stamps `--cp-current-color` inline. */
 [data-color-picker-trigger] .color-picker-trigger-swatch {
 	position: relative;
 	display: inline-block;
@@ -187,7 +188,7 @@
 	position: absolute;
 	inset: 0;
 	border-radius: inherit;
-	background: var(--cp-trigger-color, transparent);
+	background: var(--cp-current-color, transparent);
 }
 
 /* ── ValueSwatch / ValueText ─────────────────────────────────────────────── */

src/uix/soma/components/color-picker/color-picker-provider.svelte.ts

@@ -475,6 +475,23 @@ export class ColorPickerTriggerProvider {
 		() => this.opts.ariaLabel.current ?? this.provider.langs(COLOR_PICKER_LANGS.TRIGGER)
 	);
 
+	/**
+	 * Current colour as a hex string, exposed so consumers (e.g. eidos
+	 * Trigger paint) can read it without grabbing the provider via
+	 * `Provider.require()`. Falls back to `'transparent'` when no value
+	 * is set.
+	 */
+	get currentHex(): string {
+		return this.provider.opts.value.current?.hex ?? 'transparent';
+	}
+
+	/**
+	 * Inline style stamping `--cp-current-color` so eidos paints the
+	 * swatch dot purely via CSS — soma owns the value, eidos owns the
+	 * visual reading.
+	 */
+	readonly inlineStyle = $derived.by<string>(() => `--cp-current-color: ${this.currentHex}`);
+
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
 			...this.runtimePart.props,
@@ -482,7 +499,8 @@ export class ColorPickerTriggerProvider {
 			'aria-label': this.resolvedLabel,
 			'aria-haspopup': 'dialog' as const,
 			disabled: this.provider.isDisabled || undefined,
-			'data-disabled': boolToEmptyStrOrUndef(this.provider.isDisabled)
+			'data-disabled': boolToEmptyStrOrUndef(this.provider.isDisabled),
+			style: this.inlineStyle
 			// `data-state` comes from the composed PopoverTriggerProvider via mergeProps
 			// in the wrapper — we intentionally do not duplicate it here.
 		} as const)