chore: add custom samesite options to auth cookies (#16885)

Allows controlling `samesite` cookie settings from the deployment config

enterprise/cli/proxyserver.go

@@ -264,7 +264,7 @@ func (r *RootCmd) proxyServer() *serpent.Command {
 				Tracing:                tracer,
 				PrometheusRegistry:     prometheusRegistry,
 				APIRateLimit:           int(cfg.RateLimit.API.Value()),
-				SecureAuthCookie:       cfg.SecureAuthCookie.Value(),
+				CookieConfig:           cfg.HTTPCookies,
 				DisablePathApps:        cfg.DisablePathApps.Value(),
 				ProxySessionToken:      proxySessionToken.Value(),
 				AllowAllCors:           cfg.Dangerous.AllowAllCors.Value(),

enterprise/cli/testdata/coder_server_--help.golden

@@ -252,6 +252,9 @@ NETWORKING OPTIONS:
           Specifies whether to redirect requests that do not match the access
           URL host.
 
+      --samesite-auth-cookie lax|none, $CODER_SAMESITE_AUTH_COOKIE (default: lax)
+          Controls the 'SameSite' property is set on browser session cookies.
+
       --secure-auth-cookie bool, $CODER_SECURE_AUTH_COOKIE
           Controls if the 'Secure' property is set on browser session cookies.