allow Node 22 or newer, and record why it was pinned to exactly 22

The preinstall check demanded exactly 22 — `v < 22 || v > 22` — which refuses
Node 24, the current LTS. Relaxed to `>= 22`.

Recording the reason it was exact, because it was deliberate and the details are
gone: some months before now there was a real node-pty build failure that pinning
to 22 solved. Nobody remembers what it was. That is exactly the kind of decision
that gets undone twice, so it is written down here, in CLAUDE.md, and in the
project memory rather than living in one person's recollection.

What the evidence says now: node-pty 1.1.0 ships prebuilt binaries for
darwin-arm64, darwin-x64, win32-arm64 and win32-x64 — and nothing for Linux. So
its install script always falls through to `node-gyp rebuild` and compiles
against whatever Node is installed. There is no prebuilt binary, so there is no
ABI to mismatch, and node-pty declares no engines field.

That reasoning is sound and completely untested: nothing here has built node-pty
against 24, and node_modules has never existed on this machine. If `bun install`
fails building it, or officer-pty cannot load its native module, restore the exact
pin — CLAUDE.md says so, with the line to put back.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

package.json

@@ -8,7 +8,7 @@
     "src/workspaces/*"
   ],
   "scripts": {
-    "preinstall": "node -e \"var v = +process.versions.node.split('.')[0]; if (v < 22 || v > 22) { console.error('Node 22 required (got ' + process.versions.node + '). Run: nvm use 22'); process.exit(1); }\"",
+    "preinstall": "node -e \"var v = +process.versions.node.split('.')[0]; if (v < 22) { console.error('Node 22 or newer required (got ' + process.versions.node + '). Run: nvm use 22'); process.exit(1); }\"",
     "gen:index": "bun run ./scripts/gen-index.ts",
     "predev": "bun run ./scripts/gen-index.ts",
     "dev": "bun --env-file=.env --watch src/server.tsx",