admin: ui polish pass, thirty findings from the emil audit

selected states stop changing font weight, buttons gain a pressed scale and scoped 120ms transitions with a reduced-motion override, every loading and empty state reserves its height, charts measure before first paint, hit targets rise to the 44px enhanced target where layout permits, long domains clamp to two lines on an unpadded inner span, chips and name cells truncate, tabular figures on counts and time columns, a z-index layer scale replaces magic numbers and fixes the dialog-over-confirm tie, history's empty state gains a clear-filters action, page headings balance, font smoothing and color-scheme land on the html reset.

admin/src/features/overview/OverviewFrame.tsx

@@ -13,7 +13,7 @@ import { useNavigate, useSearch } from "@tanstack/react-router";
 import { Radio, RadioGroup } from "react-aria-components";
 import type { Period } from "@/lib/types";
 import { styles as shared } from "@/ui/styles";
-import { colors } from "@/ui/tokens.stylex";
+import { colors, metrics } from "@/ui/tokens.stylex";
 import { DEFAULT_PERIOD, PERIODS } from "./period";
 
 const styles = stylex.create({
@@ -33,19 +33,31 @@ const styles = stylex.create({
 		fontSize: "1.5rem",
 		lineHeight: "2rem",
 		fontWeight: 600,
+		textWrap: "balance",
 	},
 	periodGroup: {
 		display: "flex",
 		gap: "0.25rem",
 	},
+	/**
+	 * The weight lives here rather than on the selected variant: selection may
+	 * change colour, but a heavier label would re-measure the row and shift every
+	 * option beside it.
+	 */
 	period: {
 		cursor: "pointer",
+		display: "inline-flex",
+		alignItems: "center",
+		justifyContent: "center",
+		minHeight: metrics.hitTarget,
+		minWidth: metrics.hitTarget,
 		borderStyle: "none",
 		borderRadius: "0.25rem",
 		paddingInline: "0.625rem",
 		paddingBlock: "0.25rem",
 		fontSize: "0.875rem",
 		lineHeight: "1.25rem",
+		fontWeight: 500,
 	},
 	/** A Radio is a `label`, so RAC drives the ring rather than `:focus-visible`. */
 	periodFocusVisible: {
@@ -61,13 +73,20 @@ const styles = stylex.create({
 			"@media (prefers-color-scheme: dark)": "oklch(37% 0.013 285.805)",
 		},
 		color: colors.text,
-		fontWeight: 500,
 	},
 	periodIdle: {
 		backgroundColor: { default: "transparent", ":hover": colors.surfaceHover },
 		color: colors.textSecondary,
+		transitionProperty: metrics.transitionProperty,
+		transitionDuration: { default: metrics.transitionDuration, "@media (prefers-reduced-motion: reduce)": "0s" },
 	},
+	/**
+	 * The height approximates the filled overview — stat tiles, a 240px chart and
+	 * a 180px donut with the panel chrome around them — so that the page does not
+	 * jump when the window lands. That is where the number comes from.
+	 */
 	loading: {
+		minHeight: "48rem",
 		fontSize: "0.875rem",
 		lineHeight: "1.25rem",
 		color: colors.textMuted,