feat(frontend): discord registration/login/linking

also moves the registration form found on the mastodon callback page
into a component so we're not repeating the same code for every auth method

Foxnouns.Frontend/src/routes/settings/auth/+page.server.ts

@@ -0,0 +1,7 @@
+import { apiRequest } from "$api";
+import type { AuthUrls } from "$api/models/auth";
+
+export const load = async ({ fetch }) => {
+	const urls = await apiRequest<AuthUrls>("POST", "/auth/urls", { fetch, isInternal: true });
+	return { urls };
+};

Foxnouns.Frontend/src/routes/settings/auth/+page.svelte

@@ -0,0 +1,65 @@
+<script lang="ts">
+	import AuthMethodList from "$components/settings/AuthMethodList.svelte";
+	import AuthMethodRow from "$components/settings/AuthMethodRow.svelte";
+	import type { PageData } from "./$types";
+
+	type Props = { data: PageData };
+	let { data }: Props = $props();
+
+	let max = $derived(data.meta.limits.max_auth_methods);
+	let canRemove = $derived(data.user.auth_methods.length > 1);
+	let emails = $derived(data.user.auth_methods.filter((m) => m.type === "EMAIL"));
+	let discordAccounts = $derived(data.user.auth_methods.filter((m) => m.type === "DISCORD"));
+	let googleAccounts = $derived(data.user.auth_methods.filter((m) => m.type === "GOOGLE"));
+	let tumblrAccounts = $derived(data.user.auth_methods.filter((m) => m.type === "TUMBLR"));
+	let fediAccounts = $derived(data.user.auth_methods.filter((m) => m.type === "FEDIVERSE"));
+</script>
+
+{#if data.urls.email_enabled}
+	<h3>Email addresses</h3>
+	<AuthMethodList
+		methods={emails}
+		{canRemove}
+		{max}
+		buttonLink="/settings/auth/add-email"
+		buttonText="Add email address"
+	/>
+{/if}
+{#if data.urls.discord}
+	<h3>Discord accounts</h3>
+	<AuthMethodList
+		methods={discordAccounts}
+		{canRemove}
+		{max}
+		buttonLink="/settings/auth/add-discord"
+		buttonText="Link Discord account"
+	/>
+{/if}
+{#if data.urls.google}
+	<h3>Google accounts</h3>
+	<AuthMethodList
+		methods={googleAccounts}
+		{canRemove}
+		{max}
+		buttonLink="/settings/auth/add-google"
+		buttonText="Link Google account"
+	/>
+{/if}
+{#if data.urls.tumblr}
+	<h3>Tumblr accounts</h3>
+	<AuthMethodList
+		methods={tumblrAccounts}
+		{canRemove}
+		{max}
+		buttonLink="/settings/auth/add-tumblr"
+		buttonText="Link Tumblr account"
+	/>
+{/if}
+<h3>Fediverse accounts</h3>
+<AuthMethodList
+	methods={fediAccounts}
+	{canRemove}
+	{max}
+	buttonLink="/settings/auth/add-fediverse"
+	buttonText="Link Fediverse account"
+/>

Foxnouns.Frontend/src/routes/settings/auth/add-discord/+page.server.ts

@@ -0,0 +1,12 @@
+import { apiRequest } from "$api";
+import { redirect } from "@sveltejs/kit";
+
+export const load = async ({ fetch, cookies }) => {
+	const { url } = await apiRequest<{ url: string }>("GET", "/auth/discord/add-account", {
+		isInternal: true,
+		fetch,
+		cookies,
+	});
+
+	redirect(303, url);
+};