Harden TLS: enable certificate verification and SNI in inet_client.c

[fsoft72]

Description

afc_inet_client_enable_ssl() creates the TLS context and connects, but the code around src/inet_client.c:656-718 never enables certificate verification and never sets SNI.

Impact

HTTPS / SMTPS / POP3S clients can accept untrusted certificates, and some modern virtual-hosted TLS endpoints may fail without SNI.

Suggested Fix

• Call SSL_CTX_set_verify() with SSL_VERIFY_PEER
• Load system CA roots
• Check the verification result after the handshake
• Set the hostname with SSL_set_tlsext_host_name() before SSL_connect()

Priority: High — security fix
Source: IMPROVEMENTS.md #1