fix: script portability and npm security updates

Scripts:
- stop.sh: replace Linux-only fuser with cross-platform lsof fallback
- start.sh: parameterize port (APP_PORT) and container name (dynamic lookup)
- app-dev-start.sh: cross-platform stat (GNU -c / BSD -f) and setpriv/su fallback
- deploy-compose.sh: parameterize Docker registry via DOCKER_REGISTRY env var
- harden-postgres.sh: make DB_USER and DB_NAME configurable via env vars

NPM security:
- next: 15.5.12 → 15.5.15 (fixes HTTP request smuggling CVE)
- nodemailer: 8.0.1 → 8.0.5 (fixes SMTP command injection CVEs)
- lodash-es: add pnpm override to force >=4.18.0 (fixes code injection + prototype pollution)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/api/package.json

@@ -28,7 +28,7 @@
     "@trpc/server": "^11.0.0",
     "@types/nodemailer": "^7.0.11",
     "ioredis": "^5.10.0",
-    "nodemailer": "^8.0.1",
+    "nodemailer": "^8.0.5",
     "openai": "^6.27.0",
     "otpauth": "^9.5.0",
     "pino": "^10.3.1",