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/ui/Dialog.tsx

@@ -13,7 +13,7 @@
 import type { ReactNode } from "react";
 import * as stylex from "@stylexjs/stylex";
 import { Dialog as AriaDialog, Heading, Modal, ModalOverlay } from "react-aria-components";
-import { colors } from "./tokens.stylex";
+import { colors, layers, metrics } from "./tokens.stylex";
 import { styles as shared } from "./styles";
 
 interface Props {
@@ -30,7 +30,7 @@ const styles = stylex.create({
 	overlay: {
 		position: "fixed",
 		inset: 0,
-		zIndex: 50,
+		zIndex: layers.overlay,
 		display: "flex",
 		alignItems: "center",
 		justifyContent: "center",
@@ -88,10 +88,10 @@ const styles = stylex.create({
 		lineHeight: "1.75rem",
 		fontWeight: 600,
 	},
-	/** 44px on both axes: the pointer-target floor, which the word alone misses. */
+	/** The pointer-target floor on both axes, which the word alone misses. */
 	close: {
-		minWidth: 44,
-		minHeight: 44,
+		minWidth: metrics.hitTarget,
+		minHeight: metrics.hitTarget,
 		display: "inline-flex",
 		alignItems: "center",
 		justifyContent: "center",