Fix issue with auto-generated model ID during model creation

docs/API.md

@@ -659,22 +659,59 @@ attachment
 
 #### POST `/models` - 创建模型
 
-请求体:
+创建对话模型（KnowledgeQA）请求体:
 
 ```json
 {
   "name": "模型名称",
-  "type": "LLM",
-  "source": "OPENAI",
+  "type": "KnowledgeQA",  
+  "source": "remote",     # remote / local
   "description": "模型描述",
   "parameters": {
     "model": "gpt-4",
     "api_key": "sk-xxxxx",
-    "base_url": "https://api.openai.com"
+    "base_url": "xxx"
   }
 }
 ```
 
+创建嵌入模型（Embedding）请求体:
+
+```json
+{
+  "name": "模型名称",
+  "type": "Embedding",  
+  "source": "remote",     # remote / local
+  "description": "模型描述",
+  "parameters": {
+    "model": "bge-m3",
+    "api_key": "sk-xxxxx",
+    "base_url": "xxx",
+    "embedding_parameters": {
+      "dimension": 768,
+      "truncate_prompt_tokens": 512
+    }
+  }
+}
+```
+
+创建排序模型（Rerank）请求体:
+
+```json
+{
+  "name": "模型名称",
+  "type": "Rerank",  
+  "source": "remote",     # remote / local
+  "description": "模型描述",
+  "parameters": {
+    "model": "gte-reranker",
+    "api_key": "sk-xxxxx",
+    "base_url": "xxx"
+  }
+}
+```
+
+
 响应:
 
 ```json

internal/types/model.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"time"
 
+	"github.com/google/uuid"
 	"gorm.io/gorm"
 )
 
@@ -89,3 +90,15 @@ func (c *ModelParameters) Scan(value interface{}) error {
 	}
 	return json.Unmarshal(b, c)
 }
+
+// BeforeCreate is a GORM hook that runs before creating a new model record
+// Automatically generates a UUID for new models
+// Parameters:
+//   - tx: GORM database transaction
+//
+// Returns:
+//   - error: Any error encountered during the hook execution
+func (m *Model) BeforeCreate(tx *gorm.DB) (err error) {
+	m.ID = uuid.New().String()
+	return nil
+}