Fix app:dev CLI by removing deleted createOneApplication mutation (#18460)

## Summary
- The `createOneApplication` GraphQL mutation was removed from the
server during the application architecture refactor (#18432), but the
SDK CLI (`app:dev`, `app:build --sync`) still called it, causing
failures.
- Simplified the SDK to use `syncApplication` (which now internally
creates the `ApplicationEntity` via `ensureApplicationExists`) instead
of a separate create step.
- On first run (clean install), the orchestrator now runs an initial
sync before initializing the file uploader, so file uploads can proceed
(they require the `ApplicationEntity` to exist).

## Test plan
- [x] Typecheck passes for both `twenty-sdk` and `twenty-server`
- [x] `app:dev` tested locally with existing app (finds app, uploads,
syncs)
- [x] `app:dev` tested locally after `app:uninstall` (creates app via
sync, uploads, syncs)
- [x] SDK unit tests pass (23/26 files, 3 pre-existing failures
unrelated)

Made with [Cursor](https://cursor.com)

packages/twenty-front/src/modules/marketplace/graphql/mutations/registerNpmPackage.ts

@@ -1,11 +0,0 @@
-import { gql } from '@apollo/client';
-
-export const REGISTER_NPM_PACKAGE = gql`
-  mutation RegisterNpmPackage($packageName: String!) {
-    registerNpmPackage(packageName: $packageName) {
-      id
-      universalIdentifier
-      name
-    }
-  }
-`;

packages/twenty-front/src/modules/marketplace/hooks/useRegisterNpmPackage.ts

@@ -1,50 +0,0 @@
-import { useSnackBar } from '@/ui/feedback/snack-bar-manager/hooks/useSnackBar';
-import { useMutation } from '@apollo/client';
-import { t } from '@lingui/core/macro';
-import { useState } from 'react';
-import { isDefined } from 'twenty-shared/utils';
-import { REGISTER_NPM_PACKAGE } from '~/modules/marketplace/graphql/mutations/registerNpmPackage';
-
-export const useRegisterNpmPackage = () => {
-  const [registerNpmPackageMutation] = useMutation(REGISTER_NPM_PACKAGE);
-  const { enqueueErrorSnackBar, enqueueSuccessSnackBar } = useSnackBar();
-  const [isRegistering, setIsRegistering] = useState(false);
-
-  const register = async (params: {
-    packageName: string;
-  }): Promise<boolean> => {
-    setIsRegistering(true);
-
-    try {
-      const result = await registerNpmPackageMutation({
-        variables: { packageName: params.packageName },
-      });
-
-      const registration = result.data?.registerNpmPackage;
-
-      if (!isDefined(registration)) {
-        enqueueErrorSnackBar({ message: t`Registration failed.` });
-
-        return false;
-      }
-
-      enqueueSuccessSnackBar({
-        message: t`Package registered successfully.`,
-      });
-
-      return true;
-    } catch (error) {
-      const graphqlMessage = error instanceof Error ? error.message : undefined;
-
-      enqueueErrorSnackBar({
-        message: graphqlMessage ?? t`Failed to register npm package.`,
-      });
-
-      return false;
-    } finally {
-      setIsRegistering(false);
-    }
-  };
-
-  return { register, isRegistering };
-};