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/lib/components/SignUp.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import type { SupabaseClient } from '@supabase/supabase-js';
 	import { createEventDispatcher } from 'svelte';
 	const dispatch = createEventDispatcher();
 
@@ -6,17 +7,16 @@
 	let password = '';
 
 	// Access the supabase client from the layout data
-	export let supabase: any;
+	export let supabase: SupabaseClient;
 
 	async function signUpNewUser() {
 		try {
+			// `redirectTo` is not a signUp option - it was silently ignored, so the confirmation
+			// link has always used Supabase's configured site URL. Sending the user to /welcome
+			// would need `emailRedirectTo` with an absolute, allow-listed URL.
 			const { data, error } = await supabase.auth.signUp({
 				email: email,
-				password: password,
-				options: {
-					// Redirect URL after successful sign-up
-					redirectTo: '/welcome'
-				}
+				password: password
 			});
 
 			if (error) {