fix(language-core): generate auto import completion in event handler (#5426)

Author: KazariEX

packages/language-core/lib/codegen/template/elementEvents.ts

@@ -163,6 +163,7 @@ export function* generateEventExpression(
 			ctx.removeLocalVariable('$event');
 
 			yield endOfLine;
+			yield* ctx.generateAutoImportCompletion();
 			yield `}`;
 		}
 	}

packages/language-server/tests/completions.spec.ts

@@ -224,7 +224,7 @@ test.skip('Directive Modifiers', async () => {
 });
 
 test('$event argument', async () => {
-	await requestCompletionItemToTsServer('fixture.vue', 'vue', `<template><div @click="console.log($eve|)"></div></template>`, 'event');
+	await requestCompletionItemToTsServer('fixture.vue', 'vue', `<template><div @click="console.log($eve|)"></div></template>`, '$event');
 });
 
 test('<script setup>', async () => {