feat(go-models): harden ListModels for FishAudio (#15853) (#15957)

### What problem does this PR solve?

Part of #15853 (provider model-list refactor). Final two providers.

- **voyage:** Voyage AI exposes no live model-list endpoint — its public
API only has `/v1/embeddings` and `/v1/rerank` — so the previous
`ListModels` was a `no such method` stub. Replace it with a
static-catalog listing sourced from the loaded provider definition,
carrying each model's `max_tokens`, `model_types`, and embedding
`dimensions`. `list models from voyage` now returns the 13-model catalog
instead of erroring.
- **fishaudio:** route the existing `/model` voice listing through the
shared `ParseListModel` helper for consistency; keep the human-readable
`title` as the model name and fall back to `_id` when a title is blank.

#### Drive-by fix
Shared gitee_test.go `DSModelList` -> `ModelList` compile fix (renamed
in #15900); auto-resolves against the sibling #15853 PRs.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)
- [x] Refactoring

Co-authored-by: Haruko386 <tryeverypossible@163.com>

internal/entity/models/fishaudio.go

@@ -379,14 +379,19 @@ func (f *FishAudioModel) ListModels(apiConfig *APIConfig) ([]ListModelResponse,
 		return nil, fmt.Errorf("failed to parse response: %w", err)
 	}
 
-	models := make([]ListModelResponse, 0, len(result.Items))
+	modelList := ModelList{Object: "list"}
 	for _, item := range result.Items {
-		models = append(models, ListModelResponse{
-			Name: item.Title,
-		})
+		name := strings.TrimSpace(item.Title)
+		if name == "" {
+			name = strings.TrimSpace(item.ID)
+		}
+		if name == "" {
+			continue
+		}
+		modelList.Models = append(modelList.Models, DSModel{ID: name})
 	}
 
-	return models, nil
+	return ParseListModel(modelList), nil
 }
 
 func (f *FishAudioModel) Balance(apiConfig *APIConfig) (map[string]interface{}, error) {

internal/entity/models/fishaudio_test.go

@@ -0,0 +1,80 @@
+//
+//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+package models
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func newFishAudioForListModelsTest(baseURL string) *FishAudioModel {
+	return NewFishAudioModel(map[string]string{"default": baseURL}, URLSuffix{Models: "model"})
+}
+
+func TestFishAudioListModels(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			t.Errorf("method=%s, want GET", r.Method)
+		}
+		if r.URL.Path != "/model" {
+			t.Errorf("path=%s, want /model", r.URL.Path)
+		}
+		if got := r.Header.Get("Authorization"); got != "Bearer test-key" {
+			t.Errorf("Authorization=%q, want Bearer test-key", got)
+		}
+		// Fish Audio voice catalog: each item has _id and a human-readable title.
+		_, _ = io.WriteString(w, `{"items":[{"_id":"abc123","title":"Energetic Male"},{"_id":"def456","title":"Calm Female"},{"_id":"ghi789","title":""}]}`)
+	}))
+	defer srv.Close()
+
+	apiKey := "test-key"
+	models, err := newFishAudioForListModelsTest(srv.URL).ListModels(&APIConfig{ApiKey: &apiKey})
+	if err != nil {
+		t.Fatalf("ListModels: %v", err)
+	}
+	// Blank title falls back to _id; all three are returned.
+	if len(models) != 3 {
+		t.Fatalf("len(models)=%d, want 3", len(models))
+	}
+	if models[0].Name != "Energetic Male" || models[1].Name != "Calm Female" {
+		t.Fatalf("titles=%v, want [Energetic Male, Calm Female]", []string{models[0].Name, models[1].Name})
+	}
+	if models[2].Name != "ghi789" {
+		t.Fatalf("models[2].Name=%q, want fallback to _id ghi789", models[2].Name)
+	}
+}
+
+func TestFishAudioListModelsRequiresAPIKey(t *testing.T) {
+	if _, err := newFishAudioForListModelsTest("http://unused").ListModels(&APIConfig{}); err == nil {
+		t.Fatal("ListModels: expected error for missing api key, got nil")
+	}
+}
+
+func TestFishAudioListModelsRejectsHTTPError(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusUnauthorized)
+		_, _ = io.WriteString(w, `{"error":"unauthorized"}`)
+	}))
+	defer srv.Close()
+
+	apiKey := "bad-key"
+	if _, err := newFishAudioForListModelsTest(srv.URL).ListModels(&APIConfig{ApiKey: &apiKey}); err == nil {
+		t.Fatal("ListModels: expected error for HTTP 401, got nil")
+	}
+}