Path rules and trap paths match the path decoded once too (closes #85)

A path rule matched only the path as the client sent it, so /%2eenv got
past the default env-file rule while an app that decodes the path
serves /.env. A path rule now matches the path as sent or decoded once,
as a uri rule already did, and so does a path in SWWAF_TRAP_PATHS:
/%77p-login.php matches /wp-login.php. The query is cut off before the
path is decoded, and the path is decoded only once, so /%252eenv is not
/.env. A ban's notes keep the path as sent. SPEC.md and README.md say
so.

Model: opus-5-5

internal/proxy/rules.go

@@ -10,13 +10,15 @@ import (
 )
 
 // trapPath reports whether the request asks for a path in
-// SWWAF_TRAP_PATHS: its path as a path rule sees it, before any decoding
-// and without the query, is one of them. Such a request is a clear sign of
-// attack, as a ban rule's match is: it bans the client's netblock, or in
-// observe mode raises the alert for the ban it would have made.
+// SWWAF_TRAP_PATHS: its path as a path rule sees it, without the query,
+// as sent or once percent-decoded, is one of them. Such a request is a
+// clear sign of attack, as a ban rule's match is: it bans the client's
+// netblock, or in observe mode raises the alert for the ban it would have
+// made. The ban's notes give the path as sent.
 func (rq *request) trapPath(now time.Time) bool {
 	path := rules.Path(rq.in)
-	if !slices.Contains(rq.h.config.TrapPaths, path) {
+	if !slices.Contains(rq.h.config.TrapPaths, path) &&
+		!slices.Contains(rq.h.config.TrapPaths, rules.DecodeOnce(path)) {
 		return false
 	}