chore: add changeset for custom export type declaration fix

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: boazpoolman

.changeset/fix-type-declarations-for-custom-exports.md

@@ -0,0 +1,9 @@
+---
+'@strapi/sdk-plugin': patch
+---
+
+fix type declarations not being generated for custom exports
+
+Previously, only `./strapi-admin` and `./strapi-server` exports would produce `.d.ts` files when a `types` field was defined in `package.json`. Custom exports silently skipped type generation because no per-bundle tsconfig existed for them.
+
+The build now falls back to the project root `tsconfig.build.json` or `tsconfig.json` when no per-bundle tsconfig is found, so any export with a `types` field will correctly emit type declarations.