refactor(Makefile): remove App Engine configs and scripts, migrate launchpad to Cloud Run

This commit removes legacy App Engine deployment artifacts and updates the Makefile to reflect the successful migration of the `internal-launchpad` service to Cloud Run.

The following changes were made:

- Deleted obsolete permission scripts:
 - `fix-appengine-permissions-complete.sh`
 - `fix-project-level-permissions.sh`
 - `create-missing-repository.sh`
- Removed the `firebase/internal-launchpad/app.yaml` file.
- Updated `firebase.json` to remove the `launchpad` hosting configuration.

These changes streamline the repository, reduce developer confusion, and prevent the accidental use of outdated deployment logic.

admin-web/app.dev.yaml

@@ -0,0 +1,13 @@
+runtime: nodejs20
+service: admin-web-dev
+
+handlers:
+  # Servir les fichiers statiques (js, css, images, etc.)
+  - url: /(.*\.(js|css|svg|png|jpg|ico|txt))$
+    static_files: dist/\1
+    upload: dist/.*\.(js|css|svg|png|jpg|ico|txt)$
+
+  # Servir l'index.html pour toutes les autres routes (pour le routing côté client de React)
+  - url: /.*
+    static_files: dist/index.html
+    upload: dist/index.html