fix(picker-shell): footer buttons scale with picker size (xs/sm/md/lg)

The footer buttons (Clear / Cancel / Done) were hardcoded to control-height-sm
+ font-size-sm + space-3 padding regardless of the host picker's size. At
xs the buttons looked oversized next to a compact picker; at lg they
looked undersized.

- picker-shell.css: refactored button rules to consume four `--_picker-shell-*`
  CSS vars (control-h, padding-x, font, gap, row-spacing). Defaults match
  the previous sm sizing. Added explicit xs/md/lg variant blocks keyed off
  `[data-popover-content][data-picker-size='X']`.
- date-picker-content / date-range-picker-content / time-picker-content /
  time-range-picker-content / color-picker-content: forward the picker's
  resolvedSize to the popover via a separate `data-picker-size` attr,
  independent from the popover chrome's clamped `data-size`.

This decouples the popover's own chrome (which still clamps xs → sm because
the popover layer has no xs variant) from the picker-shell button scaling,
which now uses the picker's true size.

Verified at /uix/components/date-picker:
- xs → 22 / 12px (control-height-xxs, font-size-xs)
- sm → 30 / 14px (default)
- md → 36 / 16px
- lg → 44 / 16px

Also fixes the horizontal scroll at xs that surfaced the issue. The
date-picker.css `[data-popover-content]:has(...)` rule lets the popover
grow to max-content when it hosts a calendar / grid.

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

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

@@ -24,6 +24,7 @@
 	{sideOffset}
 	{collisionPadding}
 	size={resolvedSize}
+	data-picker-size={resolvedSize}
 	data-color-picker-content=""
 >
 	{#snippet children(snippetProps)}

src/uix/eidos/components/date-picker/date-picker-content.svelte

@@ -67,6 +67,7 @@
 	{sideOffset}
 	{collisionPadding}
 	size={popoverSize}
+	data-picker-size={resolvedSize}
 	style={composedStyle}
 >
 	{#snippet children(snippetProps)}

src/uix/eidos/components/date-picker/date-picker-month-view.svelte

@@ -3,7 +3,8 @@
 	import { CalendarDate } from '$libs/days';
 	import { MonthGrid } from '../month-grid';
 	import type { MonthValue, MonthPlaceholder } from '$soma/components/month-grid';
-	import type { MonthGridProviderSnippetProps } from '../month-grid';
+	import type { MonthGridProviderSnippetProps, MonthGridSize } from '../month-grid';
+	import { getDatePickerVisualContext } from './context.svelte';
 	import type { HTMLAttributes } from 'svelte/elements';
 
 	// Month-grid view for `kind='month'`. Internally renders the standalone
@@ -20,6 +21,8 @@
 	const _props: MonthViewProps = $props();
 
 	const provider = DatePickerProvider.require();
+	const visual = getDatePickerVisualContext();
+	const size = $derived((visual?.getSize() ?? 'md') as MonthGridSize);
 
 	const anchor = $derived(provider.opts.value.current ?? provider.opts.placeholder.current);
 
@@ -53,6 +56,7 @@
 	placeholder={monthPlaceholder}
 	{onValueChange}
 	{onPlaceholderChange}
+	{size}
 	locale={provider.opts.locale.current}
 	disabled={provider.opts.disabled.current}
 	readonly={provider.opts.readonly.current}

src/uix/eidos/components/date-picker/date-picker-year-view.svelte

@@ -3,7 +3,8 @@
 	import { CalendarDate } from '$libs/days';
 	import { YearGrid } from '../year-grid';
 	import type { YearValue, YearPlaceholder } from '$soma/components/year-grid';
-	import type { YearGridProviderSnippetProps } from '../year-grid';
+	import type { YearGridProviderSnippetProps, YearGridSize } from '../year-grid';
+	import { getDatePickerVisualContext } from './context.svelte';
 	import type { HTMLAttributes } from 'svelte/elements';
 
 	// Year-grid view for `kind='year'`. Internally renders the standalone
@@ -20,6 +21,8 @@
 	const _props: YearViewProps = $props();
 
 	const provider = DatePickerProvider.require();
+	const visual = getDatePickerVisualContext();
+	const size = $derived((visual?.getSize() ?? 'md') as YearGridSize);
 
 	const anchor = $derived(provider.opts.value.current ?? provider.opts.placeholder.current);
 
@@ -52,6 +55,7 @@
 	placeholder={yearPlaceholder}
 	{onValueChange}
 	{onPlaceholderChange}
+	{size}
 	locale={provider.opts.locale.current}
 	disabled={provider.opts.disabled.current}
 	readonly={provider.opts.readonly.current}

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

@@ -197,7 +197,21 @@
 /* ── Year-view + Month-view (kind='year' / 'month') ──────────────────────── */
 /* DatePicker.MonthView and DatePicker.YearView now delegate to the
    standalone MonthGrid / YearGrid primitives, so their visuals come from
-   `month-grid.css` and `year-grid.css`. No local rules needed. */
+   `month-grid.css` and `year-grid.css`. */
+
+/* The popover content uses a size-based base width (popover-min-width-{sm,md,…})
+   that can be narrower than the picker-shell footer's intrinsic content
+   (Clear / Cancel / Save buttons + gaps). Let the popover grow to max-content
+   when it hosts a date-picker calendar / grid so the inner row never overflows
+   and produces a horizontal scrollbar. */
+[data-popover-content]:has(
+		> [data-date-picker-calendar],
+		> [data-month-grid],
+		> [data-year-grid]
+	) {
+	inline-size: max-content;
+	min-inline-size: max-content;
+}
 
 @media (prefers-reduced-motion: reduce) {
 	[data-date-picker-trigger] {

src/uix/eidos/components/date-range-picker/date-range-picker-content.svelte

@@ -67,6 +67,7 @@
 	{sideOffset}
 	{collisionPadding}
 	size={popoverSize}
+	data-picker-size={resolvedSize}
 	style={composedStyle}
 >
 	{#snippet children(snippetProps)}

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

@@ -8,11 +8,20 @@
  */
 
 [data-picker-footer] {
+	/* Size-scaling vars. Defaults match `sm`. The host picker scopes these
+	 * via `[data-popover-content][data-picker-size='X']` so xs/md/lg tune
+	 * the button row to match the picker. */
+	--_picker-shell-control-h: var(--control-height-sm);
+	--_picker-shell-padding-x: var(--space-3);
+	--_picker-shell-font: var(--font-size-sm);
+	--_picker-shell-gap: var(--space-2);
+	--_picker-shell-row-spacing: var(--space-3);
+
 	display: flex;
 	align-items: center;
-	gap: var(--space-2);
-	padding-block-start: var(--space-3);
-	margin-block-start: var(--space-3);
+	gap: var(--_picker-shell-gap);
+	padding-block-start: var(--_picker-shell-row-spacing);
+	margin-block-start: var(--_picker-shell-row-spacing);
 	border-block-start: var(--border-width) solid var(--color-border-subtle);
 }
 
@@ -25,14 +34,14 @@
 [data-picker-cancel],
 [data-picker-close] {
 	inline-size: max-content;
-	min-block-size: var(--control-height-sm);
-	padding-inline: var(--space-3);
+	min-block-size: var(--_picker-shell-control-h);
+	padding-inline: var(--_picker-shell-padding-x);
 	border-radius: var(--radius-md);
 	border: var(--border-width) solid transparent;
 	background: transparent;
 	color: var(--color-content-primary);
 	font: inherit;
-	font-size: var(--font-size-sm);
+	font-size: var(--_picker-shell-font);
 	line-height: var(--leading-ui);
 	cursor: pointer;
 	transition:
@@ -41,6 +50,32 @@
 		color var(--duration-fast) var(--ease-default);
 }
 
+/* Size variants — host pickers emit `data-picker-size` on the popover
+ * content so portaled descendants can scale. The button row inherits
+ * the picker's size; popover chrome (padding / min-width) keeps its
+ * own size variant via [data-size]. */
+[data-popover-content][data-picker-size='xs'] [data-picker-footer] {
+	--_picker-shell-control-h: var(--control-height-xxs);
+	--_picker-shell-padding-x: var(--space-2);
+	--_picker-shell-font: var(--font-size-xs);
+	--_picker-shell-gap: var(--space-1-5);
+	--_picker-shell-row-spacing: var(--space-2);
+}
+
+[data-popover-content][data-picker-size='md'] [data-picker-footer] {
+	--_picker-shell-control-h: var(--control-height-md);
+	--_picker-shell-padding-x: var(--space-3-5);
+	--_picker-shell-font: var(--font-size-md);
+}
+
+[data-popover-content][data-picker-size='lg'] [data-picker-footer] {
+	--_picker-shell-control-h: var(--control-height-lg);
+	--_picker-shell-padding-x: var(--space-4);
+	--_picker-shell-font: var(--font-size-md);
+	--_picker-shell-gap: var(--space-2-5);
+	--_picker-shell-row-spacing: var(--space-4);
+}
+
 [data-picker-clear]:hover,
 [data-picker-cancel]:hover {
 	background: var(--color-surface-overlay);

src/uix/eidos/components/time-picker/time-picker-content.svelte

@@ -63,6 +63,7 @@
 	{sideOffset}
 	{collisionPadding}
 	size={resolvedSize}
+	data-picker-size={resolvedSize}
 	style={composedStyle}
 >
 	{#snippet children(snippetProps)}

src/uix/eidos/components/time-range-picker/time-range-picker-content.svelte

@@ -63,6 +63,7 @@
 	{sideOffset}
 	{collisionPadding}
 	size={resolvedSize}
+	data-picker-size={resolvedSize}
 	style={composedStyle}
 >
 	{#snippet children(snippetProps)}