⬆️ chore(deps): upgrade all dependencies to latest versions (#4)

* ⬆️ chore(deps): upgrade all dependencies to latest versions

Ran npm-check-updates -u across the manifest. No major version bumps
were available: pg and ws are both still on major 8 upstream, so this
is the latest of everything, not a major-version migration.

- pg   ^8.20.0 -> ^8.22.0 (transitively pg-protocol 1.13.0 -> 1.15.0,
  pg-pool 3.13.0 -> 3.14.0, pg-connection-string 2.12.0 -> 2.14.0,
  pg-cloudflare 1.3.0 -> 1.4.0)
- ws   ^8.19.0 -> ^8.21.1

Clears both open Dependabot alerts, both against ws:
- high   GHSA-96hv-2xvq-fx4p memory exhaustion DoS (fixed in 8.21.0)
- medium GHSA-58qx-3vcg-4xpx uninitialized memory disclosure (8.20.1)

No source changes were needed. The only APIs this repo touches are
WebSocketServer from ws and Pool/Pool.query from pg, both unchanged.

npm audit now reports 0 vulnerabilities.

* ⬆️ chore: standardize on Node 24

- Dockerfile: node:22-alpine -> node:24-alpine
- package.json: add engines.node >=24

Verified: npm ci + npm test 25/25 pass, npm audit 0 vulns,
docker build succeeds, running 24-alpine image serves
/health -> {"status":"ok"} (HTTP 200).

Author: luiscosio

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:22-alpine
+FROM node:24-alpine
 WORKDIR /app
 COPY package.json package-lock.json ./
 RUN npm ci --omit=dev

package-lock.json

@@ -7,8 +7,11 @@
     "start": "node server.js",
     "test": "node --test"
   },
+  "engines": {
+    "node": ">=24"
+  },
   "dependencies": {
-    "pg": "^8.20.0",
-    "ws": "^8.19.0"
+    "pg": "^8.22.0",
+    "ws": "^8.21.1"
   }
 }