Refactor Mihomo proxy to support WebSocket upgrades and enhance alias forwarding

- Introduced a new function `newAliasForward` to handle alias remapping for users, improving the flexibility of the proxy.
- Updated `NewMihomoForward` to differentiate between HTTP and WebSocket requests, ensuring proper handling of both types.
- Enhanced comments for clarity on the proxy behavior and request handling, improving maintainability.

internal/proxy/forward.go

@@ -17,6 +17,18 @@ func NewAliasForward(
 	stripPrefix, pathPrefix, auth string,
 	rt http.RoundTripper,
 	errHandler func(http.ResponseWriter, *http.Request, error),
+) http.Handler {
+	return newAliasForward(target, stripPrefix, pathPrefix, auth, rt, errHandler, true)
+}
+
+// newAliasForward is the shared HTTP forwarder. remapUsers maps top-level "users" → "stats/users"
+// for Telemt; Mihomo must pass false so /users is not rewritten.
+func newAliasForward(
+	target *url.URL,
+	stripPrefix, pathPrefix, auth string,
+	rt http.RoundTripper,
+	errHandler func(http.ResponseWriter, *http.Request, error),
+	remapUsers bool,
 ) http.Handler {
 	if errHandler == nil {
 		errHandler = defaultForwardErrorHandler
@@ -35,7 +47,7 @@ func NewAliasForward(
 		}
 		rest := strings.TrimPrefix(p, stripPrefix)
 		rest = strings.TrimPrefix(rest, "/")
-		if (r.Method == http.MethodGet || r.Method == http.MethodHead) && rest == "users" {
+		if remapUsers && (r.Method == http.MethodGet || r.Method == http.MethodHead) && rest == "users" {
 			rest = "stats/users"
 		}