chore(deps): SvelteKit 3 with adapter-static 4 and TypeScript 6, full-tree npm audit (#5021)

Merges Renovate's kit 3 (PR #149) and adapter-static 4 (PR #148) bumps,
plus the migration they need. The mechanical part is `sv migrate
sveltekit-3`, run one task at a time and reviewed:

- svelte.config.js is gone. Its options move into sveltekit() in
  vite.config.ts, exported as kitOptions so vitest.config.ts runs the
  same kit setup, including the $test-utils alias the tests import.
- $lib becomes #lib through package.json "imports". There is no
  src/lib/index, so only the "#lib/*" entry is kept.
- tsconfig extends $app/tsconfig.
- Peer floors raised to kit 3's requirements: svelte ^5.57.1, vite
  ^8.0.12, svelte-check ^4.7.5.

By hand, from the codemod's list of non-automated tasks:

- goto's replaceState option is now replace; keepFocus becomes
  reset: false. For the search typeahead, reset: false also stops the
  scroll-to-top, which is wanted while typing.
- The test setup mocks drop pushState/replaceState and $app/paths
  base/assets, which kit 3 removed, and mock refreshAll in place of
  invalidateAll.
- The other flagged files only read page.url or goto internal routes,
  so they needed no change.

TypeScript goes to ^6, not the ^7 Renovate offers: kit 3 declares
typescript ^6 as a peer and svelte-check 4.7 accepts ^5 || ^6. Move to
7 once both accept it.

With Tailwind 4 and kit 3 in, `npm audit` on the whole tree reports 0,
so the web lane now audits every dependency rather than only what
ships to browsers.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/lib/components/AcoustIDCard.test.ts

@@ -1,15 +1,15 @@
 import { afterEach, describe, expect, test, vi } from "vitest";
 import { render, screen, fireEvent, waitFor } from "@testing-library/svelte";
-import type { AcoustIDOverview } from "$lib/api/admin";
+import type { AcoustIDOverview } from "#lib/api/admin.js";
 
-vi.mock("$lib/api/admin", () => ({
+vi.mock("#lib/api/admin.js", () => ({
   getAcoustID: vi.fn(),
   updateAcoustIDSettings: vi.fn(),
   runAcoustIDLookup: vi.fn(),
   listUnsettledAcoustID: vi.fn(),
 }));
 
-vi.mock("$lib/stores/toast.svelte", () => ({ pushToast: vi.fn() }));
+vi.mock("#lib/stores/toast.svelte.js", () => ({ pushToast: vi.fn() }));
 
 import AcoustIDCard from "./AcoustIDCard.svelte";
 import {
@@ -17,7 +17,7 @@ import {
   listUnsettledAcoustID,
   runAcoustIDLookup,
   updateAcoustIDSettings,
-} from "$lib/api/admin";
+} from "#lib/api/admin.js";
 
 const base: AcoustIDOverview = {
   settings: { enabled: true, min_score: 0.85, api_key_set: true },