// Package misc provides miscellaneous utility functions for the CLI Proxy API server.// It includes helper functions for HTTP header manipulation and other common operations// that don't fit into more specific packages.package misc import (	"net/http"	"strings") // ScrubProxyAndFingerprintHeaders removes all headers that could reveal// proxy infrastructure, client identity, or browser fingerprints from an// outgoing request. This ensures requests to upstream services look like they// originate directly from a native client rather than a third-party client// behind a reverse proxy.func ScrubProxyAndFingerprintHeaders(req *http.Request) {	if req == nil {		return	} 	// --- Proxy tracing headers ---	req.Header.Del("X-Forwarded-For")	req.Header.Del("X-Forwarded-Host")	req.Header.Del("X-Forwarded-Proto")	req.Header.Del("X-Forwarded-Port")	req.Header.Del("X-Real-IP")	req.Header.Del("Forwarded")	req.Header.Del("Via") 	// --- Client identity headers ---	req.Header.Del("X-Title")	req.Header.Del("X-Stainless-Lang")	req.Header.Del("X-Stainless-Package-Version")	req.Header.Del("X-Stainless-Os")	req.Header.Del("X-Stainless-Arch")	req.Header.Del("X-Stainless-Runtime")	req.Header.Del("X-Stainless-Runtime-Version")	req.Header.Del("Http-Referer")	req.Header.Del("Referer") 	// --- Browser / Chromium fingerprint headers ---	// These are sent by Electron-based clients (e.g. CherryStudio) using the	// Fetch API, but NOT by Node.js https module (which Antigravity uses).	req.Header.Del("Sec-Ch-Ua")	req.Header.Del("Sec-Ch-Ua-Mobile")	req.Header.Del("Sec-Ch-Ua-Platform")	req.Header.Del("Sec-Fetch-Mode")	req.Header.Del("Sec-Fetch-Site")	req.Header.Del("Sec-Fetch-Dest")	req.Header.Del("Priority") 	// --- Encoding negotiation ---	// Antigravity (Node.js) sends "gzip, deflate, br" by default;	// Electron-based clients may add "zstd" which is a fingerprint mismatch.	req.Header.Del("Accept-Encoding")} // EnsureHeader ensures that a header exists in the target header map by checking// multiple sources in order of priority: source headers, existing target headers,// and finally the default value. It only sets the header if it's not already present// and the value is not empty after trimming whitespace.//// Parameters://   - target: The target header map to modify//   - source: The source header map to check first (can be nil)//   - key: The header key to ensure//   - defaultValue: The default value to use if no other source provides a valuefunc EnsureHeader(target http.Header, source http.Header, key, defaultValue string) {	if target == nil {		return	}	if source != nil {		if val := strings.TrimSpace(source.Get(key)); val != "" {			target.Set(key, val)			return		}	}	if strings.TrimSpace(target.Get(key)) != "" {		return	}	if val := strings.TrimSpace(defaultValue); val != "" {		target.Set(key, val)	}}