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 <noreply@anthropic.com>

src/routes/projects/money-tracker/+page.server.ts

@@ -1,4 +1,4 @@
-import { db } from '$lib/server/db';
+import { db } from '#lib/server/db/index.js';
 import {
 	moneyAccounts,
 	moneyTransactions,
@@ -9,8 +9,8 @@ import {
 	moneyWishlist,
 	moneyInsurances,
 	moneyProjectionSettings
-} from '$lib/server/db/schema';
-import { requireAdmin } from '$lib/server/authorization';
+} from '#lib/server/db/schema/index.js';
+import { requireAdmin } from '#lib/server/authorization.js';
 import {
 	type ImportedTransaction,
 	cadence,
@@ -22,7 +22,7 @@ import {
 	textField,
 	utilityKind,
 	validDate
-} from '$lib/server/money-tracker';
+} from '#lib/server/money-tracker.js';
 import { and, asc, desc, eq } from 'drizzle-orm';
 import { error, redirect } from '@sveltejs/kit';
 import type { Actions, PageServerLoad } from './$types';