fix: Add missing app directory copy step to GitHub Actions

- Add 'Copy App to Workspace' step to both workflows
- This matches our working Docker setup which mounts app to /zephyr_workspace/app
- Fixes 'ERROR: source directory app does not exist' failure
- Ensures the app directory is available in the workspace before building

This should resolve the GitHub Actions build failure.

Author: RobertDaleSmith

.github/workflows/build.yml

@@ -30,6 +30,10 @@ jobs:
           west init -m https://github.com/nrfconnect/sdk-nrf.git --mr main
           west update --narrow -o=--depth=1
 
+      - name: 📁 Copy App to Workspace
+        run: |
+          cp -r app /zephyr_workspace/app
+
       - name: 💾 Cache ~/.cache/ccache
         uses: actions/cache@v3
         with:

.github/workflows/ci.yml

@@ -45,6 +45,10 @@ jobs:
           west init -m https://github.com/nrfconnect/sdk-nrf.git --mr main
           west update --narrow -o=--depth=1
 
+      - name: 📁 Copy App to Workspace
+        run: |
+          cp -r app /zephyr_workspace/app
+
       - name: 💾 Cache ~/.cache/ccache
         uses: actions/cache@v3
         with: