fix(packaging): make .deb install and upgrade actually work end-to-end (#70)

- Generate internal CA + CA-signed web TLS cert in postinst (port 443 was
  falling back to plain HTTP because no cert files existed)
- Repair stale sqlx migration checksums for upgrades from <= 1.1.7
- Restore health check as advisory only (never fails the install)
- Use runuser instead of sudo (sudo is not guaranteed on minimal images)
- Replace predictable /tmp password file with mktemp under /run
- Frontend assets root-owned read-only (security)
- Drop Pre-Depends: postgresql-16 (misuse); drop argon2 dep (unused)
- Add openssl, curl, cron, util-linux as proper dependencies

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "patch-manager-ui",
   "private": true,
-  "version": "1.1.12",
+  "version": "1.1.13",
   "type": "module",
   "scripts": {
     "dev": "vite",