refactor(ux): combined sources to one section

- Renamed "Documents" section to "Sources" in the dashboard layout.
- Updated routing for adding sources and managing documents.
- Refactored the connectors and documents upload pages to redirect to the new sources section.
- Added localization support for the new "Sources" terminology in English and Chinese.

surfsense_web/components/sources/GridPattern.tsx

@@ -0,0 +1,23 @@
+export function GridPattern() {
+	const columns = 41;
+	const rows = 11;
+	return (
+		<div className="flex bg-gray-100 dark:bg-neutral-900 flex-shrink-0 flex-wrap justify-center items-center gap-x-px gap-y-px scale-105">
+			{Array.from({ length: rows }).map((_, row) =>
+				Array.from({ length: columns }).map((_, col) => {
+					const index = row * columns + col;
+					return (
+						<div
+							key={`${col}-${row}`}
+							className={`w-10 h-10 flex flex-shrink-0 rounded-[2px] ${
+								index % 2 === 0
+									? "bg-gray-50 dark:bg-neutral-950"
+									: "bg-gray-50 dark:bg-neutral-950 shadow-[0px_0px_1px_3px_rgba(255,255,255,1)_inset] dark:shadow-[0px_0px_1px_3px_rgba(0,0,0,1)_inset]"
+							}`}
+						/>
+					);
+				})
+			)}
+		</div>
+	);
+}