Rename internal/proxy to internal/servewaf (closes #173)

The package passes nothing to an app since rproxy took that over, so it
is named after the command it serves. Its constructor is New, like
rproxy's. The rproxy tests call their stand-in for servewaf standIn,
since a local servewaf would hide the package. No change of behaviour.

Model: opus-5-5

internal/rproxy/rproxy.go

@@ -22,7 +22,7 @@ import (
 	"time"
 
 	"sneak.berlin/go/smallwebwaf/internal/config"
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
+	"sneak.berlin/go/smallwebwaf/internal/servewaf"
 )
 
 // How rproxy keeps connections to the app and to servewaf open between
@@ -85,7 +85,7 @@ func New(params Params) *Server {
 		transport:         newTransport(),
 		serveWAFTransport: newServeWAFTransport(),
 		reportURL: (&url.URL{
-			Scheme: backend.Scheme, Host: backend.Host, Path: proxy.ReportPath,
+			Scheme: backend.Scheme, Host: backend.Host, Path: servewaf.ReportPath,
 		}).String(),
 	}
 
@@ -166,7 +166,7 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	rq := h.newRequest(w, r)
 	defer rq.finish(r.Context())
 
-	if r.Method == http.MethodGet && r.URL.Path == proxy.HealthPath {
+	if r.Method == http.MethodGet && r.URL.Path == servewaf.HealthPath {
 		rq.answerHealth()
 
 		return
@@ -199,9 +199,9 @@ func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	rq.noteAnswer(answer)
 
 	switch rq.disposition {
-	case proxy.DispositionAllow:
+	case servewaf.DispositionAllow:
 		rq.passToApp(r.Context())
-	case proxy.DispositionClose:
+	case servewaf.DispositionClose:
 		// This panic has Go's server close the connection without an answer,
 		// and log nothing; the deferred finish still runs.
 		panic(http.ErrAbortHandler)