fix: restore format selection on navigation

src/lib/components/functional/FormatDropdown.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
 	import { duration, fade, transition } from "$lib/animation";
 	import { m } from "$lib/paraglide/messages";
-	import { isMobile, files } from "$lib/store/index.svelte";
+	import { isMobile, files, dropdownStates } from "$lib/store/index.svelte";
 	import type { Categories } from "$lib/types";
 	import clsx from "clsx";
 	import { ChevronDown, SearchIcon } from "lucide-svelte";
@@ -167,6 +167,14 @@
 		selected = option;
 		open = false;
 
+		// save user's selection to dropdownStates for this session
+		if (file) {
+			dropdownStates.update((states) => {
+				const updated = { ...states, [file.name]: option };
+				return updated;
+			});
+		}
+
 		// find the category of this option if it's not in the current category
 		if (
 			currentCategory &&

src/lib/store/index.svelte.ts

@@ -417,6 +417,7 @@ export const gradientColor = writable("");
 export const goingLeft = writable(false);
 export const dropping = writable(false);
 export const vertdLoaded = writable(false);
+export const dropdownStates = writable<Record<string, string>>({});
 
 export const isMobile = writable(false);
 export const effects = writable(true);

src/routes/convert/+page.svelte

@@ -12,6 +12,7 @@
 		gradientColor,
 		showGradient,
 		vertdLoaded,
+		dropdownStates,
 	} from "$lib/store/index.svelte";
 	import { VertFile } from "$lib/types";
 	import {
@@ -31,6 +32,7 @@
 	import { Settings } from "$lib/sections/settings/index.svelte";
 	import { MAX_ARRAY_BUFFER_SIZE } from "$lib/store/index.svelte";
 	import { GB } from "$lib/consts";
+	import { log } from "$lib/logger";
 
 	let processedFileIds = $state(new Set<string>());
 
@@ -58,8 +60,16 @@
 
 			let targetFormat: string | undefined;
 
-			// use default format if enabled
-			if (settings.useDefaultFormat) {
+			// restore saved format (if navigated back to page for example)
+			const savedFormat = $dropdownStates[file.name];
+			if (
+				savedFormat &&
+				savedFormat !== file.from &&
+				categories[category]?.formats.includes(savedFormat)
+			) {
+				targetFormat = savedFormat;
+			} else if (settings.useDefaultFormat) {
+				// else use default format if enabled
 				let defaultFormat: string | undefined;
 				const df = settings.defaultFormat;
 				if (category === "image") defaultFormat = df.image;
@@ -76,7 +86,7 @@
 				}
 			}
 
-			// else use first available format (or if default format is same as input)
+			// or use first available format (or if default format is same as input)
 			if (!targetFormat) {
 				const firstDiff = categories[category]?.formats.find(
 					(f) => f !== file.from,