chore: format the tree and clear ruff's findings

Applies ruff format, ruff check --fix and prettier, so CI can gate on all three.
The surviving unused imports were all re-exports in __init__.py, now covered by a
per-file ignore; the pdf.js viewer and the generated openapi types join the
vendored code that eslint and prettier already skip.

frontend/src/lib/components/ui/avatar/avatar.svelte

@@ -1,15 +1,15 @@
 <script lang="ts">
-	import { Avatar as AvatarPrimitive } from "bits-ui";
-	import { cn } from "$lib/utils.js";
+	import { Avatar as AvatarPrimitive } from 'bits-ui';
+	import { cn } from '$lib/utils.js';
 
 	let {
 		ref = $bindable(null),
-		loadingStatus = $bindable("loading"),
-		size = "default",
+		loadingStatus = $bindable('loading'),
+		size = 'default',
 		class: className,
 		...restProps
 	}: AvatarPrimitive.RootProps & {
-		size?: "default" | "sm" | "lg";
+		size?: 'default' | 'sm' | 'lg';
 	} = $props();
 </script>
 
@@ -19,7 +19,7 @@
 	data-slot="avatar"
 	data-size={size}
 	class={cn(
-		"size-8 rounded-full after:rounded-full data-[size=lg]:size-10 data-[size=sm]:size-6 group/avatar relative flex shrink-0 select-none after:absolute after:inset-0 after:border after:border-border after:mix-blend-darken dark:after:mix-blend-lighten",
+		'group/avatar relative flex size-8 shrink-0 rounded-full select-none after:absolute after:inset-0 after:rounded-full after:border after:border-border after:mix-blend-darken data-[size=lg]:size-10 data-[size=sm]:size-6 dark:after:mix-blend-lighten',
 		className
 	)}
 	{...restProps}