refactor(dialog): standard modal layout, NoticeBanner design-element, softer Cancel

Dialog component:
- Title bar gets a subtle background tint + bottom border. Title is
  variant=h2 weight=600. Description tucks under the title with
  variant=body1 secondary color (replaces MUI's DialogContentText).
- Action bar gets a matching subtle tint + top border. Cancel is now
  outlined (was contained-error, which made every modal's Cancel button
  look destructive). Confirm keeps its color (primary by default,
  caller can pass error for destructive flows).
- Content area sits between with its own breathing room baked in, so
  callers no longer need mt={theme.spacing(...)} workarounds.
- The cancelColor prop is removed; sites that genuinely need a
  destructive Cancel can use confirmColor='error' on the Confirm button
  instead.

NoticeBanner design-element:
- Extracted from the inline alert pattern in PageSpeedKeyPriorityFallback
  into a reusable component with severity=info|warning|error.
- Refactored PageSpeedKeyPriorityFallback to use it.

DialogResolution.tsx: drop the now-removed cancelColor prop and the
mt-Box wrapper that's no longer needed (Dialog provides the spacing).

client/src/Components/inputs/Dialog.tsx

@@ -2,10 +2,12 @@ import Dialog from "@mui/material/Dialog";
 import type { DialogProps } from "@mui/material/Dialog";
 import DialogActions from "@mui/material/DialogActions";
 import DialogContent from "@mui/material/DialogContent";
-import DialogContentText from "@mui/material/DialogContentText";
 import DialogTitle from "@mui/material/DialogTitle";
+import Typography from "@mui/material/Typography";
+import Box from "@mui/material/Box";
 import { Button } from "@/Components/inputs";
-import { typographyLevels } from "@/Utils/Theme/Palette";
+import { LAYOUT } from "@/Utils/Theme/constants";
+import { useTheme } from "@mui/material/styles";
 import { useTranslation } from "react-i18next";
 import type { ReactNode } from "react";
 
@@ -16,7 +18,6 @@ export const DialogInput = ({
 	onConfirm,
 	onCancel,
 	confirmColor = "primary",
-	cancelColor = "error",
 	loading = false,
 	cancelText,
 	confirmText,
@@ -31,7 +32,6 @@ export const DialogInput = ({
 	onConfirm?(item: any): any;
 	onCancel?(item: any): any;
 	confirmColor?: "error" | "primary";
-	cancelColor?: "error" | "primary";
 	loading?: boolean;
 	cancelText?: string;
 	confirmText?: string;
@@ -41,6 +41,7 @@ export const DialogInput = ({
 	additionalButtons?: ReactNode;
 }) => {
 	const { t } = useTranslation();
+	const theme = useTheme();
 	return (
 		<Dialog
 			open={open}
@@ -50,16 +51,48 @@ export const DialogInput = ({
 				if (reason !== "backdropClick" && onCancel) onCancel(undefined);
 			}}
 		>
-			{title && <DialogTitle sx={{ fontSize: typographyLevels.l }}>{title}</DialogTitle>}
-			<DialogContent>
-				{content && <DialogContentText>{content}</DialogContentText>}
-				{children}
-			</DialogContent>
-			<DialogActions>
+			{title && (
+				<DialogTitle
+					sx={{
+						pb: theme.spacing(LAYOUT.XS),
+						backgroundColor: theme.palette.action.hover,
+						borderBottom: `1px solid ${theme.palette.divider}`,
+					}}
+				>
+					<Typography
+						component="span"
+						variant="h2"
+						sx={{ fontWeight: 600, display: "block" }}
+					>
+						{title}
+					</Typography>
+					{content && (
+						<Typography
+							variant="body1"
+							color="text.secondary"
+							sx={{ mt: theme.spacing(LAYOUT.XS), display: "block" }}
+						>
+							{content}
+						</Typography>
+					)}
+				</DialogTitle>
+			)}
+			{children && (
+				<DialogContent sx={{ pt: theme.spacing(LAYOUT.MD) }}>
+					<Box sx={{ pt: theme.spacing(LAYOUT.XS) }}>{children}</Box>
+				</DialogContent>
+			)}
+			<DialogActions
+				sx={{
+					p: theme.spacing(LAYOUT.MD),
+					pt: theme.spacing(LAYOUT.SM),
+					backgroundColor: theme.palette.action.hover,
+					borderTop: `1px solid ${theme.palette.divider}`,
+				}}
+			>
 				<Button
 					loading={loading}
-					variant="contained"
-					color={cancelColor}
+					variant="outlined"
 					onClick={onCancel}
 				>
 					{cancelText ?? t("common.buttons.cancel")}