chore: bump version to 1.3.16

Set `options.outbase = 'src'` in the esbuildOptions callback to ensure
output files preserve the correct directory structure relative to the
`src` folder, preventing path flattening during the build process.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@zen/core",
-  "version": "1.3.15",
+  "version": "1.3.16",
   "description": "Un CMS Next.js construit sur l'essentiel, rien de plus, rien de moins.",
   "repository": {
     "type": "git",

tsup.config.js

@@ -78,6 +78,7 @@ export default defineConfig([
     ],
     bundle: false, // Don't bundle these files
     esbuildOptions(options) {
+      options.outbase = 'src';
       options.loader = {
         '.js': 'jsx',
         '.jsx': 'jsx',