feat: upgrade to SvelteKit 3 and adapter-bun

Run the sveltekit-3 migration and finish its manual tasks:

- Move kit config into the sveltekit() Vite plugin; drop svelte.config.js
- Replace $lib with #lib subpath imports
- Declare env vars in src/env.ts and import them from $app/env/{private,public}
- Consolidate param matchers into src/params.ts
- Use error(status, message), Response.json, refreshAll and goto reset/shallow
- Fall back to a full page load when goto rejects a login return path

Switch from adapter-node to adapter-bun: the build script runs Vite under
Bun (the adapter requires it) and the image starts with `bun ./build`.
Runtime env names (PORT, BODY_SIZE_LIMIT, ADDRESS_HEADER, ...) are unchanged.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/routes/projects/animaldex/register/+page.svelte

@@ -1,16 +1,16 @@
 <script lang="ts">
-	import { Button } from '$lib/components/ui/button/index.js';
-	import { Input } from '$lib/components/ui/input/index.js';
-	import { Textarea } from '$lib/components/ui/textarea/index.js';
+	import { Button } from '#lib/components/ui/button/index.js';
+	import { Input } from '#lib/components/ui/input/index.js';
+	import { Textarea } from '#lib/components/ui/textarea/index.js';
 	import { resolve } from '$app/paths';
 	import type { Map as MaptilerMap, Marker as MaptilerMarker } from '@maptiler/sdk';
 	import { onDestroy, onMount } from 'svelte';
-	import { page } from '$app/stores';
+	import { page } from '$app/state';
 	import { goto } from '$app/navigation';
 	import ArrowLeft from 'lucide-svelte/icons/arrow-left';
 	import X from 'lucide-svelte/icons/x';
 
-	const animalId = $derived($page.url.searchParams.get('animalId'));
+	const animalId = $derived(page.url.searchParams.get('animalId'));
 	const isNewSighting = $derived(!!animalId);
 
 	let species = $state('');
@@ -95,16 +95,16 @@
 		if (!mapContainer || lat === null || lng === null) return;
 		try {
 			const { Map, Marker, config } = await import('@maptiler/sdk');
-			const { env } = await import('$env/dynamic/public');
+			const { PUBLIC_MAPTILER_API_KEY } = await import('$app/env/public');
 			if (destroyed) return;
-			if (!env.PUBLIC_MAPTILER_API_KEY) {
+			if (!PUBLIC_MAPTILER_API_KEY) {
 				mapError = 'The map is not configured yet. Your GPS location is still available.';
 				return;
 			}
-			config.apiKey = env.PUBLIC_MAPTILER_API_KEY;
+			config.apiKey = PUBLIC_MAPTILER_API_KEY;
 			map = new Map({
 				container: mapContainer,
-				style: `https://api.maptiler.com/maps/satellite/style.json?key=${env.PUBLIC_MAPTILER_API_KEY}`,
+				style: `https://api.maptiler.com/maps/satellite/style.json?key=${PUBLIC_MAPTILER_API_KEY}`,
 				center: [lng!, lat!],
 				zoom: 15
 			});
@@ -181,7 +181,7 @@
 				for (const file of photoFiles) {
 					const uploadForm = new FormData();
 					uploadForm.set('photo', file);
-					const uploadRes = await fetch(resolve('/projects/animaldex/api/upload'), {
+					const uploadRes = await fetch(resolve('projects/animaldex/api/upload'), {
 						method: 'POST',
 						body: uploadForm
 					});
@@ -193,8 +193,8 @@
 			if (reporterName) localStorage.setItem('reporterName', reporterName);
 
 			const endpoint = isNewSighting
-				? resolve(`/projects/animaldex/api/animals/${animalId}/sightings`)
-				: resolve('/projects/animaldex/api/animals');
+				? resolve(`projects/animaldex/api/animals/${animalId}/sightings`)
+				: resolve('projects/animaldex/api/animals');
 			const body = isNewSighting
 				? {
 						animalId,
@@ -229,7 +229,7 @@
 				const err = await res.json();
 				throw new Error(err.message ?? 'Submission failed');
 			}
-			goto(resolve('/projects/animaldex?submitted=1'));
+			goto(resolve('projects/animaldex?submitted=1'));
 		} catch (e: unknown) {
 			submitError = e instanceof Error ? e.message : 'Something went wrong.';
 		} finally {
@@ -244,7 +244,7 @@
 
 <section class="mx-auto max-w-3xl px-4 py-10 sm:px-6 sm:py-14">
 	<a
-		href={resolve('/projects/animaldex')}
+		href={resolve('projects/animaldex')}
 		class="inline-flex items-center gap-1 text-base text-[var(--site-muted)] hover:text-[var(--site-text)]"
 		><ArrowLeft size={16} aria-hidden="true" /> animaldex</a
 	>