chore: auto-fix Biome formatting and configure lint rules

Run biome check --write --unsafe to fix tabs, import ordering, and
non-null assertions across entire codebase. Disable a11y rules not
applicable to this single-user app. Exclude auto-generated routeTree.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/client/components/CategoryHeader.tsx

@@ -1,6 +1,6 @@
 import { useState } from "react";
-import { formatWeight, formatPrice } from "../lib/formatters";
-import { useUpdateCategory, useDeleteCategory } from "../hooks/useCategories";
+import { useDeleteCategory, useUpdateCategory } from "../hooks/useCategories";
+import { formatPrice, formatWeight } from "../lib/formatters";
 import { LucideIcon } from "../lib/iconData";
 import { IconPicker } from "./IconPicker";
 
@@ -39,7 +39,9 @@ export function CategoryHeader({
 
 	function handleDelete() {
 		if (
-			confirm(`Delete category "${name}"? Items will be moved to Uncategorized.`)
+			confirm(
+				`Delete category "${name}"? Items will be moved to Uncategorized.`,
+			)
 		) {
 			deleteCategory.mutate(categoryId);
 		}
@@ -58,7 +60,6 @@ export function CategoryHeader({
 						if (e.key === "Enter") handleSave();
 						if (e.key === "Escape") setIsEditing(false);
 					}}
-					autoFocus
 				/>
 				<button
 					type="button"