chore: remove IS_AI_ENABLED feature flag (#19916)

## Summary
- AI is now GA, so the public/lab `IS_AI_ENABLED` flag is removed from
`FeatureFlagKey`, the public flag catalog, and the dev seeder.
- Drops every backend `@RequireFeatureFlag(IS_AI_ENABLED)` guard (agent,
agent chat, chat subscription, role-to-agent assignment, workflow AI
step creation) and the now-unused `FeatureFlagModule`/`FeatureFlagGuard`
wiring in the AI and workflow modules.
- Removes frontend gating from settings nav, role
permissions/assignment/applicability, command menu hotkeys, side panel,
mobile/drawer nav, and the agent chat provider so AI UI is always on.
Tests and generated GraphQL/SDK schemas updated accordingly.

## Test plan
- [x] `npx nx typecheck twenty-shared`
- [x] `npx nx typecheck twenty-server`
- [x] `npx nx typecheck twenty-front`
- [x] `npx nx lint:diff-with-main twenty-server`
- [x] `npx nx lint:diff-with-main twenty-front`
- [x] `npx jest --config=packages/twenty-server/jest.config.mjs
feature-flag`
- [x] `npx jest --config=packages/twenty-server/jest.config.mjs
workspace-entity-manager`
- [ ] Manual smoke test: AI features still accessible without any flag
row in `featureFlag`

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/twenty-front/src/modules/command-menu/hooks/useCommandMenuHotKeys.ts

@@ -9,11 +9,9 @@ import { sidePanelSearchState } from '@/side-panel/states/sidePanelSearchState';
 import { useGlobalHotkeys } from '@/ui/utilities/hotkey/hooks/useGlobalHotkeys';
 import { useHotkeysOnFocusedElement } from '@/ui/utilities/hotkey/hooks/useHotkeysOnFocusedElement';
 import { useAtomStateValue } from '@/ui/utilities/state/jotai/hooks/useAtomStateValue';
-import { useIsFeatureEnabled } from '@/workspace/hooks/useIsFeatureEnabled';
 import { isNonEmptyString } from '@sniptt/guards';
 import { Key } from 'ts-key-enum';
 import { SidePanelPages } from 'twenty-shared/types';
-import { FeatureFlagKey } from '~/generated-metadata/graphql';
 
 export const useCommandMenuHotKeys = () => {
   const { toggleSidePanelMenu } = useSidePanelMenu();
@@ -31,8 +29,6 @@ export const useCommandMenuHotKeys = () => {
 
   const sidePanelPage = useAtomStateValue(sidePanelPageState);
 
-  const isAiEnabled = useIsFeatureEnabled(FeatureFlagKey.IS_AI_ENABLED);
-
   useGlobalHotkeys({
     keys: ['ctrl+k', 'meta+k'],
     callback: () => {
@@ -58,12 +54,10 @@ export const useCommandMenuHotKeys = () => {
   useGlobalHotkeys({
     keys: ['@'],
     callback: () => {
-      if (isAiEnabled) {
-        openAskAiPage({ resetNavigationStack: true });
-      }
+      openAskAiPage({ resetNavigationStack: true });
     },
     containsModifier: false,
-    dependencies: [openAskAiPage, isAiEnabled],
+    dependencies: [openAskAiPage],
     options: {
       ignoreModifiers: true,
     },