Isolate providers per client: add provider targets and a Codex-side form

internal/gateway/handlers.go

@@ -17,6 +17,7 @@ type providerInput struct {
 	BaseURL string        `json:"base_url"`
 	APIKey  string        `json:"api_key"`
 	Models  config.Models `json:"models"`
+	Target  string        `json:"target"`
 }
 
 func (s *Server) handleStatus(w http.ResponseWriter, r *http.Request) {
@@ -54,7 +55,20 @@ func (s *Server) handleStatus(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) handleListProviders(w http.ResponseWriter, r *http.Request) {
-	writeJSON(w, http.StatusOK, map[string]any{"items": s.store.Config().Providers})
+	target := r.URL.Query().Get("target")
+	switch target {
+	case "", config.TargetClaude, config.TargetCodex:
+	default:
+		writeAPIError(w, http.StatusBadRequest, `target must be "claude" or "codex"`)
+		return
+	}
+	items := []config.Provider{}
+	for _, p := range s.store.Config().Providers {
+		if target == "" || p.Target == target {
+			items = append(items, p)
+		}
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"items": items})
 }
 
 func (s *Server) handleCreateProvider(w http.ResponseWriter, r *http.Request) {
@@ -63,7 +77,7 @@ func (s *Server) handleCreateProvider(w http.ResponseWriter, r *http.Request) {
 		writeAPIError(w, http.StatusBadRequest, "invalid request body: "+err.Error())
 		return
 	}
-	p, err := s.store.AddProvider(in.Name, in.Preset, in.BaseURL, in.APIKey, in.Models)
+	p, err := s.store.AddProvider(in.Name, in.Preset, in.BaseURL, in.APIKey, in.Models, in.Target)
 	if err != nil {
 		writeAPIError(w, http.StatusBadRequest, err.Error())
 		return
@@ -78,7 +92,7 @@ func (s *Server) handleUpdateProvider(w http.ResponseWriter, r *http.Request) {
 		writeAPIError(w, http.StatusBadRequest, "invalid request body: "+err.Error())
 		return
 	}
-	p, err := s.store.UpdateProvider(id, in.Name, in.Preset, in.BaseURL, in.APIKey, in.Models)
+	p, err := s.store.UpdateProvider(id, in.Name, in.Preset, in.BaseURL, in.APIKey, in.Models, in.Target)
 	if err != nil {
 		writeAPIError(w, http.StatusBadRequest, err.Error())
 		return