aba7e2a256
Split ~1250-line sniffer.go into sniffer_http.go (HTTP handling, dial, round-trip), sniffer_tls.go (TLS MITM, termination), sniffer_h2.go (HTTP/2), sniffer_ws.go (WebSocket frame copy/record), and sniffer_rewrite.go (upgrade, body rewrite). Extract clampBodySize, normalizeHost, effectiveReadTimeout as package-level functions to simplify testing. Add 22 tests covering pure functions, option setters, HTTP proxy integration, WebSocket frame copy, and edge cases.