fix(ssl): keep panel certificate in sync after auto-renew (#12858)

The auto-renew flow in obtainSSL returned early when OpenResty was not
installed or `nginx -s reload` failed, skipping reloadSystemSSL. The new
certificate was persisted to the DB and written into website Nginx
configs, but the panel's own server.crt / server.key on disk and the
in-memory constant.CertStore were left pointing at the old material.
Because the cert was now fresh, subsequent cron ticks did not retry the
renewal, so the panel kept serving the stale cert until a user manually
re-applied it from 面板设置 → SSL.

Two changes:

1. agent/app/service/website_ssl.go
   reloadSystemSSL is now called unconditionally after a successful
   renewal, regardless of whether OpenResty is present or nginx reload
   succeeded. The function already short-circuits for non-panel SSLs,
   so this is safe.

2. agent/app/service/website_ssl.go + agent/cron/job/ssl.go
   Add SyncSystemSSL, invoked at the start of every renew cron tick.
   It compares the panel's on-disk cert/key with the WebsiteSSL row
   referenced by the SSLID setting and rewrites the files + notifies
   core when they diverge. This recovers existing installs that are
   already in the "DB ahead of disk" state and self-heals any future
   drift introduced by transient failures.
   https://github.com/1Panel-dev/1Panel/issues/12472