fix: Fix failing integration tests and update documentation

- Fix TestUpdateDevice: Use correct JSON field name and handle float64 type
- Fix TestRejectDeviceRegistration: Expect message response instead of boolean
- Update approve device docs: Add missing response fields
- Update reject device docs: Correct message text and format
- Update Bruno API: Fix example response for reject endpoint

Both integration tests now pass while maintaining API consistency.

bruno/devices/Reject Device Registration.bru

@@ -33,11 +33,10 @@ docs {
    - 404: Registration not found
    - 400: Invalid registration status
 
-  **Example Response:**
-   ```json
-   {
-     "message": "Device registration rejected",
-     "registration_id": "uuid"
-   }
-   ```
+   **Example Response:**
+    ```json
+    {
+      "message": "device registration rejected"
+    }
+    ```
 }

cmd/server/tests/device_test.go

@@ -173,7 +173,7 @@ func TestUpdateDevice(t *testing.T) {
 	updatedDevice := response["device"].(map[string]interface{})
 	assert.Equal(t, "Updated Device Name", updatedDevice["device_name"], "Should have updated name")
 	assert.Equal(t, false, updatedDevice["sync_enabled"], "Should be disabled")
-	assert.Equal(t, int32(10), updatedDevice["sync_frequency"], "Should have updated frequency")
+	assert.Equal(t, float64(10), updatedDevice["sync_frequency_minutes"], "Should have updated frequency")
 }
 
 func TestDeleteDevice(t *testing.T) {
@@ -325,5 +325,5 @@ func TestRejectDeviceRegistration(t *testing.T) {
 	var rejectResponse map[string]interface{}
 	json.Unmarshal(rec.Body.Bytes(), &rejectResponse)
 
-	assert.True(t, rejectResponse["rejected"].(bool), "Should confirm rejection")
+	assert.Equal(t, "device registration rejected", rejectResponse["message"], "Should confirm rejection message")
 }

docs/developer/api/devices/approve_device_registration.md

@@ -28,8 +28,11 @@ Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
 
 ```json
 {
-  "message": "Device registration approved",
-  "device_id": "uuid"
+  "message": "device approved successfully",
+  "device_name": "string",
+  "device_type": "string", 
+  "registration_id": "uuid",
+  "approved": true
 }
 ```
 

docs/developer/api/devices/reject_device_registration.md

@@ -28,7 +28,7 @@ Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
 
 ```json
 {
-  "message": "Device registration rejected"
+  "message": "device registration rejected"
 }
 ```