chore: finish frontend ESLint migration #18

Enable every plugin recommended preset and replace Biome with ESLint formatting.

Preserve API contracts and JSX whitespace; verify source, tests, builds and tooling.

src/app/routes/RouteTransition.tsx

@@ -1,6 +1,7 @@
+import type { FC, PropsWithChildren } from "react";
+
 import { domAnimation, LazyMotion, useReducedMotion } from "motion/react";
 import * as m from "motion/react-m";
-import type { FC, PropsWithChildren } from "react";
 import { useLocation } from "react-router";
 
 const TRANSITION_DURATION_SECONDS = 0.2;
@@ -13,9 +14,9 @@ const RouteTransition: FC<PropsWithChildren> = (props) => {
 	return (
 		<LazyMotion features={domAnimation}>
 			<m.div
-				key={pathname}
-				initial={reduceMotion ? false : { opacity: 0 }}
 				animate={{ opacity: 1 }}
+				initial={!reduceMotion && { opacity: 0 }}
+				key={pathname}
 				transition={{
 					duration: reduceMotion ? 0 : TRANSITION_DURATION_SECONDS,
 					ease: "easeOut",