Go: new CLI command, list all models and show model (#15786)

### What problem does this PR solve?

```
RAGFlow(user)> list models;
+---------------------------+------------+-------------+--------------------+---------------------------------------------+
| alias                     | max_tokens | model_types | name               | thinking                                    |
+---------------------------+------------+-------------+--------------------+---------------------------------------------+
|                           | 1048576    | [chat]      | deepseek-v4-flash  | map[clear_thinking:true default_value:true] |
|                           | 1048576    | [chat]      | deepseek-v4-pro    | map[clear_thinking:true default_value:true] |
|                           | 1024000    | [chat]      | minimax-m3         | map[clear_thinking:true default_value:true] |
|                           | 64000      | [vision]    | glm-4.5v           | map[clear_thinking:true default_value:true] |
| [baai/bge-m3]             | 8192       | [embedding] | bge-m3             |                                             |
| [baai/bge-reranker-v2-m3] | 1024       | [rerank]    | bge-reranker-v2-m3 |                                             |
|                           |            | [tts]       | step-audio-tts-3b  |                                             |
| [qwen/qwen3-asr-1.7b]     |            | [asr]       | qwen3-asr-1.7b     |                                             |
| [paddleocr-vl-1.5]        |            | [ocr]       | paddleocr-vl-0.9b  |                                             |
+---------------------------+------------+-------------+--------------------+---------------------------------------------+
RAGFlow(user)> show model 'minimax-m3';
+--------------+---------------------------------------------+
| field        | value                                       |
+--------------+---------------------------------------------+
| name         | minimax-m3                                  |
| max_tokens   | 1024000                                     |
| model_types  | [chat]                                      |
| thinking     | map[clear_thinking:true default_value:true] |
| class        |                                             |
| alias        |                                             |
| ModelTypeMap |                                             |
+--------------+---------------------------------------------+
RAGFlow(user)> show model 'baai/bge-m3';
+--------------+---------------+
| field        | value         |
+--------------+---------------+
| model_types  | [embedding]   |
| thinking     |               |
| class        |               |
| alias        | [baai/bge-m3] |
| ModelTypeMap |               |
| name         | bge-m3        |
| max_tokens   | 8192          |
+--------------+---------------+
```

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/handler/models.go

@@ -0,0 +1,98 @@
+//
+//  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 handler
+
+import (
+	"net/http"
+	"ragflow/internal/common"
+	"ragflow/internal/service"
+
+	"github.com/gin-gonic/gin"
+)
+
+// ProviderHandler provider handler
+type ModelHandler struct {
+	modelProviderService *service.ModelProviderService
+}
+
+// NewProviderHandler create provider handler
+func NewModelHandler(modelProviderService *service.ModelProviderService) *ModelHandler {
+	return &ModelHandler{
+		modelProviderService: modelProviderService,
+	}
+}
+
+type ShowModelRequest struct {
+	ModelName *string `json:"model_name"`
+	Page      int     `json:"page"`
+	PageSize  int     `json:"page_size"`
+}
+
+func (h *ModelHandler) ListAllModels(c *gin.Context) {
+
+	var req ShowModelRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		println("JSON bind error: %v (type: %T)", err, err)
+		c.JSON(http.StatusOK, gin.H{
+			"code":    common.CodeBadRequest,
+			"message": err.Error(),
+		})
+		return
+	}
+
+	if req.ModelName == nil {
+		// list models
+		page := req.Page
+		pageSize := req.PageSize
+
+		// list tenant models
+		models, err := h.modelProviderService.ListAllModels(page, pageSize)
+		if err != nil {
+			c.JSON(http.StatusOK, gin.H{
+				"code":    common.CodeDataError,
+				"message": err.Error(),
+				"data":    nil,
+			})
+			return
+		}
+
+		c.JSON(http.StatusOK, gin.H{
+			"code":    0,
+			"message": "success",
+			"data":    models,
+		})
+	} else {
+		// show model
+		model, err := h.modelProviderService.ShowModel(*req.ModelName)
+		if err != nil {
+			c.JSON(http.StatusOK, gin.H{
+				"code":    common.CodeDataError,
+				"message": err.Error(),
+				"data":    nil,
+			})
+			return
+		}
+
+		c.JSON(http.StatusOK, gin.H{
+			"code":    0,
+			"message": "success",
+			"data":    model,
+		})
+	}
+
+	return
+}