feat: adapter-auto support bun add (#12854)

* adapter-auto and bun

* changeset

* Update .changeset/serious-geckos-itch.md

Co-authored-by: Tee Ming <chewteeming01@gmail.com>

---------

Co-authored-by: Tee Ming <chewteeming01@gmail.com>

Author: RiskyMH

.changeset/serious-geckos-itch.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-auto': minor
+---
+
+feat: add support for Bun package manager

packages/adapter-auto/index.js

@@ -10,7 +10,8 @@ import process from 'node:process';
 const commands = {
 	npm: (name, version) => `npm install -D ${name}@${version}`,
 	pnpm: (name, version) => `pnpm add -D ${name}@${version}`,
-	yarn: (name, version) => `yarn add -D ${name}@${version}`
+	yarn: (name, version) => `yarn add -D ${name}@${version}`,
+	bun: (name, version) => `bun add -D ${name}@${version}`
 };
 
 function detect_lockfile() {
@@ -20,6 +21,7 @@ function detect_lockfile() {
 		if (existsSync(join(dir, 'pnpm-lock.yaml'))) return 'pnpm';
 		if (existsSync(join(dir, 'yarn.lock'))) return 'yarn';
 		if (existsSync(join(dir, 'package-lock.json'))) return 'npm';
+		if (existsSync(join(dir, 'bun.lockb')) || existsSync(join(dir, 'bun.lock'))) return 'bun';
 	} while (dir !== (dir = dirname(dir)));
 
 	return 'npm';