feat: implement complete user control

app/routes/_data.users._index/add.tsx

@@ -0,0 +1,82 @@
+import { Form, useSubmit } from '@remix-run/react'
+import { useState } from 'react'
+
+import Code from '~/components/Code'
+import Dialog from '~/components/Dialog'
+import TextField from '~/components/TextField'
+
+interface Props {
+	magic?: string
+}
+
+export default function Add({ magic }: Props) {
+	const [username, setUsername] = useState('')
+	const submit = useSubmit()
+
+	return (
+		<Dialog>
+			<Dialog.Button>
+				Add a new user
+			</Dialog.Button>
+
+			<Dialog.Panel>
+				{close => (
+					<>
+						<Dialog.Title>
+							Add a new user
+						</Dialog.Title>
+						<Dialog.Text className="mb-8">
+							Enter a username to create a new user.
+							{' '}
+							{magic
+								? (
+									<>
+										Since Magic DNS is enabled, machines will be
+										accessible via
+										{' '}
+										<Code>
+											[machine].
+											{username.length > 0 ? username : '[username]'}
+											.
+											{magic}
+										</Code>
+										.
+									</>
+									)
+								: undefined}
+						</Dialog.Text>
+						<Form
+							method="POST"
+							onSubmit={(event) => {
+								submit(event.currentTarget)
+							}}
+						>
+							<input type="hidden" name="_method" value="create" />
+							<TextField
+								label="Username"
+								placeholder="my-new-user"
+								name="username"
+								state={[username, setUsername]}
+								className="my-2"
+							/>
+							<div className="mt-6 flex justify-end gap-2 mt-6">
+								<Dialog.Action
+									variant="cancel"
+									onPress={close}
+								>
+									Cancel
+								</Dialog.Action>
+								<Dialog.Action
+									variant="confirm"
+									onPress={close}
+								>
+									Create
+								</Dialog.Action>
+							</div>
+						</Form>
+					</>
+				)}
+			</Dialog.Panel>
+		</Dialog>
+	)
+}