Fix view field updates not persisting (#16672)

Fixes an issue where column width changes and other view field
modifications were not persisted, and a toast error was shown.

**Root Causes:**
1. Frontend was using client-generated IDs instead of database IDs for
updates
2. Backend cache was stale, causing `View field to update not found`
error

**Changes:**
- Use the existing database ID when updating view fields
- Exclude client-generated IDs when creating new view fields  
- Invalidate flat entity maps cache before/after view field operations
- Refresh both view and view field caches to prevent validation errors

Fixes #16417 
Closes #16381

packages/twenty-front/src/modules/views/hooks/useSaveCurrentViewFields.ts

@@ -81,11 +81,13 @@ export const useSaveCurrentViewFields = () => {
                     position: existingField.position,
                     size: existingField.size,
                     isVisible: existingField.isVisible,
+                    aggregateOperation: existingField.aggregateOperation,
                   },
                   {
                     position: createViewFieldInput.position,
                     size: createViewFieldInput.size,
                     isVisible: createViewFieldInput.isVisible,
+                    aggregateOperation: createViewFieldInput.aggregateOperation,
                   },
                 )
               ) {
@@ -101,7 +103,7 @@ export const useSaveCurrentViewFields = () => {
                   ...viewFieldsToUpdate,
                   {
                     input: {
-                      id: createViewFieldInput.id,
+                      id: existingField.id,
                       update: {
                         aggregateOperation:
                           createViewFieldInput.aggregateOperation,