Remove commented-out code and update configurations

Deleted unused or commented-out code across multiple files to improve clarity and maintainability. Updated `kv_namespaces` in `wrangler.toml` and specified the package manager in `package.json`. Add placeholder values for development kv stores.

src/layout/NavItem.tsx

@@ -8,7 +8,6 @@ function NavItem({ path, children, color, onClick, as, cursor }) {
       href={path}
       mb={2}
       cursor={cursor}
-      // ml={5}
       mr={2}
       color={color ?? "text.accent"}
       letterSpacing="normal"