fix(docker): replace better-sqlite3 with pure-JS JSON token store

better-sqlite3 is a native C++ addon that requires compilation on Alpine
(musl libc, no pre-built binaries exist) and fails on Debian slim too
because prebuild-install cannot detect the libc type correctly.

Replace with a pure-JS JSON file token store (server/utils/tokenStore.js):
- Atomic writes via temp file + rename (no corruption on crash)
- Same API: storeToken/getToken/clearToken
- TTL enforcement on read and hourly prune
- Zero native code, zero build tools required

Dockerfile:
- Revert to node:22-alpine (was node:22-slim)
- Remove build tools (python3/make/g++) — no longer needed
- Restore wget HEALTHCHECK (available in Alpine busybox)

docker-compose.yaml: restore wget healthcheck

package.json: remove better-sqlite3 dependency

docker-compose.yaml

@@ -35,7 +35,7 @@ services:
       - ALL                     # drop all Linux capabilities
     cap_add: []                 # add back none — Node.js needs no special caps
     healthcheck:
-      test: ["CMD", "node", "-e", "require('http').get('http://localhost:3001/health',r=>{process.exit(r.statusCode===200?0:1)}).on('error',()=>process.exit(1))"]
+      test: ["CMD", "wget", "-qO-", "http://localhost:3001/health"]
       interval: 30s
       timeout: 5s
       retries: 3