fix(infra): install from monorepo root and build core before app

The app release workflow was running bun install inside packages/app,
which fetched @t-req/core from npm instead of using the workspace link.
Install from the repo root and build core first so subpath exports resolve.

Author: andrewmelchor

.github/workflows/release-app.yml

@@ -63,7 +63,10 @@ jobs:
 
       - name: Install dependencies
         run: bun install
-        working-directory: packages/app
+
+      - name: Build core (workspace dependency)
+        run: bun run build
+        working-directory: packages/core
 
       - name: Build all platform binaries
         run: bun run build:all