build: lift Vite to 8, and get the tree out of iCloud's way

The frontend build hung on 0% CPU, roughly every other run: blocked in read()
inside libuv, no output, forever. `svelte-kit sync` alone did it too, so it was
not the bundler.

The cause was not the toolchain. `~/Documents` is iCloud-managed, and iCloud
evicts what it thinks is cold — which for a dependency tree is nearly all of it:
359 of 400 sampled files under node_modules were `dataless`. Reading an evicted
file blocks until it is downloaded again, and a download that stalls hangs the
build for good. The tell was a different error entirely: Playwright once reported
`ETIMEDOUT: connection timed out, read` while loading jsconfig.json, and
ETIMEDOUT on a local file read does not exist.

Vite 5 and esbuild 0.21 predate Node 22 and this machine runs Node 26, so they
went up anyway — to Vite 8 with @sveltejs/vite-plugin-svelte 7, which SvelteKit
2.70 takes. `package-lock.json` had to be deleted for npm to resolve it; it held
plugin 4 and rejected the whole tree with ERESOLVE. That made the build faster.
It was not what was hanging.

`engines` says Node >= 22.12 now, so the next person is told rather than left
watching a process do nothing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

web/package.json

@@ -12,11 +12,14 @@
   },
   "devDependencies": {
     "@playwright/test": "^1.62.1",
-    "@sveltejs/adapter-static": "^3.0.6",
-    "@sveltejs/kit": "^2.8.0",
-    "@sveltejs/vite-plugin-svelte": "^4.0.0",
-    "svelte": "^5.1.0",
-    "svelte-check": "^4.0.0",
-    "vite": "^5.4.0"
+    "@sveltejs/adapter-static": "^3.0.10",
+    "@sveltejs/kit": "^2.70.2",
+    "@sveltejs/vite-plugin-svelte": "^7.3.0",
+    "svelte": "^5.56.9",
+    "svelte-check": "^4.7.6",
+    "vite": "^8.2.1"
+  },
+  "engines": {
+    "node": ">=22.12"
   }
 }