Add comprehensive tests for the ValidateSession wrapper function covering:
- Non-existent token (returns false)
- Empty token (returns false)
- Valid token (returns true)
- Expired token (returns false)
The ValidateSession function is a simple wrapper around the SessionStore's
ValidateSession method, but having direct tests ensures the wrapper is
exercised and documents its expected behavior.
Coverage: ValidateSession 0% → 100%
Tests for detectProxy, isConnectionSecure, getCookieSettings, and
generateSessionToken functions. Covers proxy detection for various
headers including X-Forwarded-For, CF-Ray, Forwarded (RFC 7239),
and secure connection detection via TLS and proxy headers.
