fix: repair defects surfaced by gating CI on lint and typecheck

`npm run check` reported 15 errors and `npm run lint` 20, all pre-existing, so
neither gate could pass. Fixing them turned up three real bugs:

- SignOut destructured `{ error }` off `.then(() => {})`, which resolves to
  undefined, so every sign-out threw a TypeError - after the signed-out event had
  already been emitted. Sign-out also left the user on the protected page they
  were on, still showing its content; it now returns them to the home page and
  re-runs the server loads.

- SignUp passed `redirectTo`, which is not a signUp option and was silently
  ignored, so the confirmation link has always used Supabase's configured site
  URL. Documented rather than changed, since pointing it elsewhere needs an
  absolute allow-listed URL.

- The Pokédex page tracked totalRecordsCreated but never passed it to the box
  view, so the "Processed N entries so far" progress message never rendered.

The rest is typing and dead code: cookie callback parameters in hooks.server.ts
and +layout.ts, the untyped supabase props, a query-builder type that made
PostgREST rows untyped downstream, an unused session destructure, and
`while (true)` paging loops rewritten as `for (;;)`.

src/routes/+page.svelte

@@ -1,7 +1,5 @@
 <script lang="ts">
-	import { onDestroy, onMount } from 'svelte';
-	import { user } from '$lib/stores/user.js';
-	import { type User } from '@supabase/auth-js';
+	import { onMount } from 'svelte';
 	import SignUp from '$lib/components/SignUp.svelte';
 	import { goto } from '$app/navigation';
 
@@ -9,12 +7,7 @@
 	let { supabase, stats } = data;
 	$: ({ supabase, stats } = data);
 
-	let localUser: User | null;
-	const unsubscribe = user.subscribe((value) => {
-		localUser = value;
-	});
-	onDestroy(unsubscribe);
-
+	// Redirection is decided from the live session below, so the user store is not needed here.
 	let isCheckingSession = true;
 
 	onMount(() => {