fix: account for config.kit.paths.base when building with `adapter-…

…cloudflare` (#10604)

fixes #10290

Correctly includes the base path config setting when resolving the path to the _app directory.

.changeset/eighty-cats-wave.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-cloudflare': patch
+---
+
+fix: correctly include `config.kit.paths.base`

packages/adapter-cloudflare/index.js

@@ -36,7 +36,7 @@ export default function (options = {}) {
 				JSON.stringify(get_routes_json(builder, written_files, options.routes ?? {}), null, '\t')
 			);
 
-			writeFileSync(`${dest}/_headers`, generate_headers(builder.config.kit.appDir), { flag: 'a' });
+			writeFileSync(`${dest}/_headers`, generate_headers(builder.getAppPath()), { flag: 'a' });
 
 			builder.copy(`${files}/worker.js`, `${tmp}/_worker.js`, {
 				replace: {
@@ -87,7 +87,7 @@ function get_routes_json(builder, assets, { include = ['/*'], exclude = ['<all>'
 		.flatMap((rule) => (rule === '<all>' ? ['<build>', '<files>', '<prerendered>'] : rule))
 		.flatMap((rule) => {
 			if (rule === '<build>') {
-				return `/${builder.config.kit.appDir}/*`;
+				return `/${builder.getAppPath()}/*`;
 			}
 
 			if (rule === '<files>') {

packages/kit/src/exports/public.d.ts

@@ -119,7 +119,7 @@ export interface Builder {
 	getClientDirectory(): string;
 	/** Get the fully resolved path to the directory containing server-side code. */
 	getServerDirectory(): string;
-	/** Get the application path including any configured `base` path, e.g. `/my-base-path/_app`. */
+	/** Get the application path including any configured `base` path, e.g. `my-base-path/_app`. */
 	getAppPath(): string;
 
 	/**