perf(pokedex): send the box grid as packed rows with the page

The server load fetched a full combined-data page at a 9999 item page size,
carrying detail text and ownership fields the grid never renders, and the client
re-fetched the same payload after hydration.

Load a trimmed grid row instead and pack it as positional tuples so field names
are not repeated for every one of a thousand-plus entries. Entry detail is
fetched on demand from the new per-entry endpoint when a cell is opened, and the
grid marks itself interactive so other page-start work can queue behind it.

src/routes/api/pokedexes/[id]/entries/[entryId]/+server.ts

@@ -0,0 +1,18 @@
+import { error, json } from '@sveltejs/kit';
+import { requireAuth } from '$lib/utils/auth';
+import PokedexRepository from '$lib/repositories/PokedexRepository';
+import { loadPokedexEntryDetail } from '$lib/services/PokedexGridService';
+import type { RequestHandler } from './$types';
+
+export const GET: RequestHandler = async (event) => {
+	const userId = await requireAuth(event);
+	const entryId = Number(event.params.entryId);
+	if (!Number.isSafeInteger(entryId) || entryId < 1) throw error(400, 'Invalid entry');
+	const pokedex = await new PokedexRepository(event.locals.supabase, userId).findById(
+		event.params.id
+	);
+	if (!pokedex) throw error(404, 'Pokédex not found');
+	const detail = await loadPokedexEntryDetail(event.locals.supabase, userId, pokedex, entryId);
+	if (!detail) throw error(404, 'Entry not found');
+	return json(detail, { headers: { 'cache-control': 'private, no-store' } });
+};

src/routes/api/pokedexes/[id]/grid/+server.ts

@@ -0,0 +1,29 @@
+import { packGrid } from '$lib/models/PokedexGridRow';
+import { error, json } from '@sveltejs/kit';
+import { requireAuth } from '$lib/utils/auth';
+import PokedexRepository from '$lib/repositories/PokedexRepository';
+import { loadPokedexGrid } from '$lib/services/PokedexGridService';
+import { PokedexPerformance } from '$lib/server/pokedexPerformance';
+import type { RequestHandler } from './$types';
+
+export const GET: RequestHandler = async (event) => {
+	const timings = new PokedexPerformance();
+	const userId = await timings.measure('auth', () => requireAuth(event));
+	const pokedex = await timings.measure('ownership', () =>
+		new PokedexRepository(event.locals.supabase, userId).findById(event.params.id)
+	);
+	if (!pokedex) throw error(404, 'Pokédex not found');
+	const grid = await loadPokedexGrid(event.locals.supabase, userId, pokedex, timings);
+	const packed = timings.prepare(() => packGrid(grid));
+	timings.recordAuth(event.locals.pokedexAuthMs);
+	const timing = timings.finish();
+	return json(
+		{ grid: packed },
+		{
+			headers: {
+				'cache-control': 'private, no-store',
+				...(timing ? { 'server-timing': timing } : {})
+			}
+		}
+	);
+};