fix: remove conflicting root page and fix CSV import export

- Remove scaffolded +page.svelte that conflicted with (public) route group
- Change PET_FIELDS from export to local const (SvelteKit disallows)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/routes/+page.svelte

@@ -1,2 +0,0 @@
-<h1>Welcome to SvelteKit</h1>
-<p>Visit <a href="https://svelte.dev/docs/kit">svelte.dev/docs/kit</a> to read the documentation</p>

src/routes/admin/import/+page.server.ts

@@ -8,7 +8,7 @@ import type { Role } from '$lib/roles';
 import { logAudit } from '$lib/server/audit';
 
 // Pet fields that can be mapped from CSV
-export const PET_FIELDS = [
+const PET_FIELDS = [
 	{ key: 'name', label: 'Name', required: true },
 	{ key: 'species', label: 'Species (dog/cat/other)' },
 	{ key: 'breed', label: 'Breed' },