[FRONT COMPONENTS] Headless components (#18096)

## Description

- Add `isHeadless` field to `FrontComponent` entity so front components
can run without rendering UI in the command menu
- Introduce headless front component mounting logic:
`HeadlessFrontComponentMountRoot` at the application root,
`useMountHeadlessFrontComponent`, and `useUnmountHeadlessFrontComponent`
hooks to mount/unmount headless components
- Expand the SDK with new action components (`Action`, `ActionLink`,
`ActionOpenSidePanelPage`) and host communication functions
(`openSidePanelPage`, `unmountFrontComponent`)
- Move `CommandMenuPages` type to twenty-shared so the SDK can reference
it for side panel navigation

## Video QA



https://github.com/user-attachments/assets/4f9e3bb1-fcd1-42be-b3f4-a97e80c2add2

packages/twenty-front/src/modules/front-components/components/FrontComponentRenderer.tsx

@@ -20,7 +20,7 @@ export const FrontComponentRenderer = ({
   const theme = useTheme();
   const { enqueueErrorSnackBar } = useSnackBar();
   const { executionContext, frontComponentHostCommunicationApi } =
-    useFrontComponentExecutionContext();
+    useFrontComponentExecutionContext({ frontComponentId });
 
   const handleError = useCallback(
     (error?: Error) => {

packages/twenty-front/src/modules/front-components/components/HeadlessFrontComponentMountRoot.tsx

@@ -0,0 +1,31 @@
+import { Suspense, lazy } from 'react';
+
+import { useRecoilValue } from 'recoil';
+
+import { mountedHeadlessFrontComponentIdsState } from '@/front-components/states/mountedHeadlessFrontComponentIdsState';
+
+const FrontComponentRenderer = lazy(() =>
+  import('@/front-components/components/FrontComponentRenderer').then(
+    (module) => ({ default: module.FrontComponentRenderer }),
+  ),
+);
+
+export const HeadlessFrontComponentMountRoot = () => {
+  const mountedHeadlessFrontComponentIds = useRecoilValue(
+    mountedHeadlessFrontComponentIdsState,
+  );
+
+  if (mountedHeadlessFrontComponentIds.size === 0) {
+    return null;
+  }
+
+  return (
+    <>
+      {[...mountedHeadlessFrontComponentIds].map((frontComponentId) => (
+        <Suspense key={frontComponentId} fallback={null}>
+          <FrontComponentRenderer frontComponentId={frontComponentId} />
+        </Suspense>
+      ))}
+    </>
+  );
+};