When TLS ClientHello has no SNI extension (ServerName is empty),
normalizeHost returns empty string. Both sniffer_tls.go paths (sniffing
and forwarder packages) previously still called dial with an empty host,
cascading 'missing port in address' errors through connector, router,
and service layers.
Now returns early with a debug-level log, silently closing the
connection instead of attempting to dial upstream.
Pull node-resolution logic out of dial/dialTLS into pure resolveHTTPNode
and resolveTLSNode helpers. This separates node selection (bypass, hop,
fallback) from connection establishment, making both independently
testable. Add 21 new tests covering bypass, hop selection, nil-hop,
addr fallback, upgrade response type mismatch, websocket frames,
response body rewriting, and h2 preface validation.