feat: remove Gin and standardize on nethttp

transport/internal/routing/pattern.go

@@ -58,7 +58,7 @@ func Parse(method, path string, handler http.Handler) []Segment {
 	return segments
 }
 
-// CheckConflict enforces Gin-compatible ambiguity rules for one method.
+// CheckConflict enforces the portable ambiguity rules for one method.
 func CheckConflict(existing, next []Segment) {
 	for i := 0; i < len(existing) && i < len(next); i++ {
 		a, b := existing[i], next[i]