Fix twenty-sdk typecheck race condition (#18246)

## Fix SDK first-run build failure when generated API client is missing

### Problem

When running `twenty app:dev` for the first time, the build pipeline
crashes because:

1. The esbuild front-component watcher tries to resolve
`twenty-sdk/generated`, but the generated API client doesn't exist yet —
it's only created later in the pipeline after syncing with the server.
2. The typecheck plugin (`tsc --noEmit`) runs as a blocking esbuild
`onStart` hook, so even with stub files, type errors on the empty client
classes (e.g. `Property 'query' does not exist on type 'CoreApiClient'`)
cause the build to fail before the real client can be generated.

This creates a chicken-and-egg problem: the watchers need the generated
client to build, but the client is generated after the watchers produce
their output.

### Solution

**1. Stub generated client on startup**

Added `ensureGeneratedClientStub` to `ClientService` that writes minimal
placeholder files (`CoreApiClient`, `MetadataApiClient`) into
`node_modules/twenty-sdk/generated/` if the directory doesn't already
exist. This is called in `DevModeOrchestrator.start()` before any
watchers are created, so the `twenty-sdk/generated` import always
resolves.

**2. Skip typecheck on first sync round**

Made the esbuild typecheck plugin accept a `shouldSkipTypecheck`
callback. The orchestrator starts with `skipTypecheck = true` and passes
`() => this.skipTypecheck` through the watcher chain. After the real API
client is generated, the flag is flipped to `false`, so subsequent
rebuilds enforce full type checking with the real generated types.

packages/twenty-sdk/src/cli/utilities/dev/orchestrator/dev-mode-orchestrator.ts

@@ -29,6 +29,8 @@ export class DevModeOrchestrator {
   private syncTimer: NodeJS.Timeout | null = null;
   private serverCheckInterval: NodeJS.Timeout | null = null;
 
+  private clientService: ClientService;
+  private skipTypecheck = true;
   private checkServerStep: CheckServerOrchestratorStep;
   private ensureValidTokensStep: EnsureValidTokensOrchestratorStep;
   private buildManifestStep: BuildManifestOrchestratorStep;
@@ -44,7 +46,7 @@ export class DevModeOrchestrator {
 
     const apiService = new ApiService({ disableInterceptors: true });
     const configService = new ConfigService();
-    const clientService = new ClientService();
+    this.clientService = new ClientService();
     const stepDeps = { state: this.state, notify: () => this.state.notify() };
 
     this.checkServerStep = new CheckServerOrchestratorStep({
@@ -64,7 +66,7 @@ export class DevModeOrchestrator {
     this.uploadFilesStep = new UploadFilesOrchestratorStep(stepDeps);
     this.generateApiClientStep = new GenerateApiClientOrchestratorStep({
       ...stepDeps,
-      clientService,
+      clientService: this.clientService,
       configService,
     });
     this.syncApplicationStep = new SyncApplicationOrchestratorStep({
@@ -75,6 +77,7 @@ export class DevModeOrchestrator {
       ...stepDeps,
       scheduleSync: this.scheduleSync.bind(this),
       onFileBuilt: this.handleFileBuilt.bind(this),
+      shouldSkipTypecheck: () => this.skipTypecheck,
     });
   }
 
@@ -84,6 +87,10 @@ export class DevModeOrchestrator {
     await fs.ensureDir(outputDir);
     await fs.emptyDir(outputDir);
 
+    await this.clientService.ensureGeneratedClientStub({
+      appPath: this.state.appPath,
+    });
+
     await this.startWatchersStep.start();
 
     this.serverCheckInterval = setInterval(() => {
@@ -200,6 +207,8 @@ export class DevModeOrchestrator {
         appPath: this.state.appPath,
       });
 
+      this.skipTypecheck = false;
+
       await this.uploadFilesStep.copyAndUploadApiClientFiles(
         this.state.appPath,
       );

packages/twenty-sdk/src/cli/utilities/dev/orchestrator/steps/start-watchers-orchestrator-step.ts

@@ -30,6 +30,7 @@ export class StartWatchersOrchestratorStep {
   private scheduleSync: () => void;
   private notify: () => void;
   private onFileBuilt: (event: FileBuiltEvent) => void;
+  private shouldSkipTypecheck: () => boolean;
 
   private manifestWatcher: ManifestWatcher | null = null;
   private logicFunctionsWatcher: EsbuildWatcher | null = null;
@@ -43,11 +44,13 @@ export class StartWatchersOrchestratorStep {
     scheduleSync: () => void;
     notify: () => void;
     onFileBuilt: (event: FileBuiltEvent) => void;
+    shouldSkipTypecheck: () => boolean;
   }) {
     this.state = options.state;
     this.scheduleSync = options.scheduleSync;
     this.notify = options.notify;
     this.onFileBuilt = options.onFileBuilt;
+    this.shouldSkipTypecheck = options.shouldSkipTypecheck;
   }
 
   async start(): Promise<void> {
@@ -166,6 +169,7 @@ export class StartWatchersOrchestratorStep {
     this.logicFunctionsWatcher = createLogicFunctionsWatcher({
       appPath: this.state.appPath,
       sourcePaths,
+      shouldSkipTypecheck: this.shouldSkipTypecheck,
       handleBuildError: this.handleFileBuildError.bind(this),
       handleFileBuilt: this.handleFileBuilt.bind(this),
     });
@@ -179,6 +183,7 @@ export class StartWatchersOrchestratorStep {
     this.frontComponentsWatcher = createFrontComponentsWatcher({
       appPath: this.state.appPath,
       sourcePaths,
+      shouldSkipTypecheck: this.shouldSkipTypecheck,
       handleBuildError: this.handleFileBuildError.bind(this),
       handleFileBuilt: this.handleFileBuilt.bind(this),
     });