fix: Restore ForkTsCheckerWebpackPlugin with build:true

Critical fix: ForkTsCheckerWebpackPlugin with 'build: true' is required
to generate .d.ts files for plugin packages. Without this, the Docker
build fails because TypeScript can't resolve imports from packages
that haven't had their type definitions built.

This restores the plugin with the essential configuration while still
using SWC for fast transpilation.

Author: rusackas

superset-frontend/webpack.config.js

@@ -191,33 +191,26 @@ if (!isDevMode) {
   );
 }
 
-// Type checking only in production builds
-// In Docker/CI, this runs after transpilation to catch type errors
+// TypeScript type checking configuration
+// SWC handles transpilation, but we still need ForkTsCheckerWebpackPlugin
+// to generate .d.ts files for the plugin packages
 if (!isDevMode) {
-  // Check if plugins have been built (required for type checking)
-  const pluginsBuilt = require('fs').existsSync(
-    path.join(__dirname, 'packages/superset-ui-core/lib/index.d.ts'),
-  );
-
-  if (pluginsBuilt) {
-    plugins.push(
-      new ForkTsCheckerWebpackPlugin({
-        async: false,
-        typescript: {
-          memoryLimit: 4096,
-          configOverwrite: {
-            compilerOptions: {
-              skipLibCheck: true,
-            },
+  plugins.push(
+    new ForkTsCheckerWebpackPlugin({
+      async: false,
+      typescript: {
+        memoryLimit: 4096,
+        build: true, // CRITICAL: Generate .d.ts files for plugins
+        mode: 'write-references', // Handle project references
+        configOverwrite: {
+          compilerOptions: {
+            skipLibCheck: true,
+            incremental: true,
           },
         },
-      }),
-    );
-  } else {
-    console.warn(
-      '⚠️ TypeScript checking disabled - run "npm run plugins:build" first',
-    );
-  }
+      },
+    }),
+  );
 }
 
 const PREAMBLE = [path.join(APP_DIR, '/src/preamble.ts')];