Bring the checklist app under version control

The project has lived only as a folder on the Mac Studio and, briefly, as a
transfer tarball. This is the first commit: the Express server and its web
front end, the Capacitor iOS and Android wrappers, and the release and backup
scripts.

The repo is the source, not a backup of the machine. Left out on purpose, by
the .gitignore files that were already in the tree: node_modules, build output,
mobile/www (regenerated from server/public on every build), and server/data,
which holds the live checklists and belongs on the NAS rather than in git.

Every credential is excluded too — server/.env, the Play upload keystore and
its properties file, the App Store Connect key and ios-signing.config. The one
secret that was not in an ignored file was the NAS SSH password, hard-coded in
build-deploy.sh and grepped back out of it by backup-to-drive.sh. Both now read
it from the login keychain (service checklist-nas, account Christian), falling
back to NAS_PASS in the environment, so rotating it is one keychain entry
rather than a history rewrite.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

mobile/android/variables.gradle

@@ -0,0 +1,16 @@
+ext {
+    minSdkVersion = 24
+    compileSdkVersion = 36
+    targetSdkVersion = 36
+    androidxActivityVersion = '1.11.0'
+    androidxAppCompatVersion = '1.7.1'
+    androidxCoordinatorLayoutVersion = '1.3.0'
+    androidxCoreVersion = '1.17.0'
+    androidxFragmentVersion = '1.8.9'
+    coreSplashScreenVersion = '1.2.0'
+    androidxWebkitVersion = '1.14.0'
+    junitVersion = '4.13.2'
+    androidxJunitVersion = '1.3.0'
+    androidxEspressoCoreVersion = '3.7.0'
+    cordovaAndroidVersion = '14.0.1'
+}