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/request.go

@@ -16,9 +16,9 @@ import (
 	"sync/atomic"
 	"time"
 
-	"sneak.berlin/go/smallwebwaf/internal/proxy"
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 	"sneak.berlin/go/smallwebwaf/internal/rules"
+	"sneak.berlin/go/smallwebwaf/internal/servewaf"
 )
 
 // flushAfterEachWrite has ReverseProxy pass on each part of the app's answer as
@@ -129,7 +129,7 @@ func (rq *request) readFirstPartOfBody() bool {
 	}
 
 	_ = rq.rc.SetReadDeadline(rq.requestDeadline())
-	held, err := io.ReadAll(io.LimitReader(rq.body, proxy.QuestionBodyMaxBytes))
+	held, err := io.ReadAll(io.LimitReader(rq.body, servewaf.QuestionBodyMaxBytes))
 	// From here on, the request timer ends a read of the rest of the body, so that
 	// the answer can name the side rproxy was waiting on.
 	_ = rq.rc.SetReadDeadline(time.Time{})
@@ -384,7 +384,7 @@ func (rq *request) finish(ctx context.Context) {
 		return
 	}
 
-	report := &proxy.Report{
+	report := &servewaf.Report{
 		RequestID:     rq.id,
 		Status:        min(rq.out.status, reportStatusMax),
 		RequestBytes:  requestBytes,