fix: 修复若干问题，添加java lsp

backend/internal/api/handler_test.go

@@ -28,6 +28,14 @@ func (f *fakeCompletionService) Complete(_ context.Context, _ completion.Request
 	return f.resp, nil
 }
 
+type fakeLSPStatusProvider struct {
+	status map[string]any
+}
+
+func (f *fakeLSPStatusProvider) LspServiceStatus() map[string]any {
+	return f.status
+}
+
 // 验证 HTTP 补全接口的成功路径。
 func TestRegisterRoutesCompletionSuccess(t *testing.T) {
 	gin.SetMode(gin.TestMode)
@@ -174,3 +182,41 @@ func TestRegisterRoutesCompletionWebSocketSuccess(t *testing.T) {
 		t.Fatalf("unexpected items: %+v", resp.Items)
 	}
 }
+
+// 验证 /health/lsp-status 会返回语言探测状态快照。
+func TestRegisterRoutesLspStatus(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	r := gin.New()
+	RegisterRoutes(r, &fakeCompletionService{}, RouteOptions{
+		LSPStatusProvider: &fakeLSPStatusProvider{
+			status: map[string]any{
+				"go": map[string]any{
+					"online": true,
+				},
+			},
+		},
+	})
+
+	req := httptest.NewRequest(http.MethodGet, "/health/lsp-status", nil)
+	w := httptest.NewRecorder()
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Fatalf("expected status 200, got %d", w.Code)
+	}
+
+	var got map[string]any
+	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
+		t.Fatalf("failed to decode response: %v", err)
+	}
+	if got["status"] != "ok" {
+		t.Fatalf("expected status ok, got %#v", got["status"])
+	}
+	languages, ok := got["languages"].(map[string]any)
+	if !ok {
+		t.Fatalf("languages field type mismatch: %#v", got["languages"])
+	}
+	if _, ok := languages["go"]; !ok {
+		t.Fatalf("expected go language status, got %#v", languages)
+	}
+}