Enhance API path normalization and configuration validation

- Introduced a new function to normalize request URL paths, collapsing duplicate slashes and clearing raw paths to ensure correct routing in the reverse proxy.
- Updated the gateway to utilize the normalization function for API requests, improving routing consistency.
- Trimmed whitespace from server configuration fields in the validation process to prevent potential issues with malformed URLs.
- Enhanced documentation in GATEWAY_RUN.md to clarify the importance of proper URL formatting and configuration.

internal/proxy/reverse.go

@@ -4,9 +4,32 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"net/url"
+	"path"
 	"strings"
 )
 
+// NormalizeRequestURLPath collapses duplicate slashes and dot-segments in req.URL.Path
+// (path.Clean) and clears RawPath so strip-prefix routing matches the client path even
+// when the request line contained "//" (e.g. /api//mtg/health). Without this, the path
+// may not match /api/{alias} and SingleHostReverseProxy forwards a wrong path upstream.
+func NormalizeRequestURLPath(req *http.Request) {
+	if req == nil || req.URL == nil {
+		return
+	}
+	u := req.URL
+	if u.Path == "" {
+		u.Path = "/"
+		u.RawPath = ""
+		return
+	}
+	c := path.Clean(u.Path)
+	if !strings.HasPrefix(c, "/") {
+		c = "/" + c
+	}
+	u.Path = c
+	u.RawPath = ""
+}
+
 // NewReverseProxy builds a reverse proxy to target base URL with path rewriting:
 // stripPrefix (/api/{alias}) + pathPrefix (/v1) + remainder, joined onto target via url.JoinPath
 // (e.g. https://host/api/ + v1 + health → https://host/v1/health).
@@ -20,6 +43,7 @@ func NewReverseProxy(target *url.URL, stripPrefix, pathPrefix string, setAuth st
 	orig := proxy.Director
 	targetQuery := target.RawQuery
 	proxy.Director = func(req *http.Request) {
+		NormalizeRequestURLPath(req)
 		p := req.URL.Path
 		if !strings.HasPrefix(p, stripPrefix) {
 			orig(req)